CRPS/RSD Glossary

Dr. Howard Black

This list makes no claim to completeness, and will likely always be a work in progress. If you see an omission or have a suggestion, please let me know. It would be much appreciated! Currently, there are over 750 entries in the Glossary, and more are always being added.

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(it's the same one on the first page of this site). If that doesn't do it, here's a great guide (pdf)!

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ABASIA - Lack of motor or muscular coordination in walking.

ABATEMENT - A decrease in the severity or intensity of a symptom.ablation

ABLATION - Surgical removal or destruction of a part of the body, such as amputation of a limb. The agents used range from phenol (an acid) to radiofrequency (RF)-generated heat. For chronic pain, ablation is seldom effective.

ACAMPSIA - Inability to bend or extend a joint.

ACANTHESTHSIA - A feeling of "pins and needles", or like an extremity is "asleep".

ACETAMINOPHEN - aka Tylenol®, as well as a boatload of generics, the most popular OTC analgesic drug there is. Is commonly compounded with opioids to produce some of the most popular Rx drugs on the market: Tylenol-3®, Vicodin®, Percocet®, and a host of others. The downside is that acetaminophen is a cumulative hepatotoxin, and serious liver damage can result from using more than 3g (3,000mg) of acetaminophen per day for an extended period of time.

ACETYLCHOLINE - A neurotransmitter. Acetylcholine (ACh) in vertebrates is the major transmitter at neuromuscular junctions, autonomic acetylcholineganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. It is generally not used as an administered drug because it is broken down very rapidly by cholinesterases in the blood, but it is useful in some ophthalmological applications.

ACROAGNOSIS - Lack of sensation in an arm or leg.

ACRONESTHESIA - Loss of sensation in one or more limbs. acrocyanosis

ACROCYANOSIS - Blueness of the hands and feet, caused by a multitude of possible etiologies. In many cases, it isn't pathological and requires no treatment.

ACROEDEMA - Swelling of the hands and feet.

ACROHYPERHYDROSIS - Excessive sweating of the hands and feet.

ACROTIC PULSE - A very weak pulse.

ACTINOCYMOGRAPHY - X-raying an organ while it is in motion. active site

ACTIVE SITE - the small, 3D pocket in a receptor with which a drug (ligand, substrate) associates to form a drug-receptor (or enzyme-substrate) complex.

active transportACTIVE TRANSPORT - the movement of molecules or ions across a cell membrane, from an area of lower to higher concentration. This requires energy, usually from adenosine triphosphate (ATP).

ACTIVITY, INTRINSIC - The property of a drug which determines the amount of biological effect produced per unit of drug-receptor complex formed. Two agents combining with equivalent sets of receptors may not produce equal degrees of effect even if both agents are given in maximally effective doses; the agents differ in their intrinsic activities and the one producing the greater maximum effect has the greater intrinsic activity. Intrinsic activity is not the same as "potency" and may be completely independent of it.

acupunctureACUPUNCTURE - The science of using thin needles to stimulate various specific gates in the meridian system, which, according to Eastern philosophy and practice, carries one's life energy, or qi (). Many Eastern countries (China, Vietnam, S. Korea, Japan, etc.) have been using acupuncture in standard medicine for over 5000 years.

ACUTE - Rapid; short, sudden, severe. By definition, the effects occur between 1 min. and 1 hr. following drug ingestion. Compare with chronic. addictions

ADDICTION - a state defined by compulsive engagement in rewarding stimuli, despite adverse consequences. It is a disease or biological process leading to such behaviors. Synonymous with dependence. The best definition I've ever heard: "Addiction is the compulsive repetition of any act or behavior that causes us shame".

ADENOSINE TRIPHOSPHATE (ATP) - an energy-bearing molecule found in all living cells. Formation of nucleic acids, transmission of nerve impulses, muscle contraction, and many other energy-consuming reactions of metabolism are made possible by the energy in ATP molecules.

ADHESION - Abnormal adherence of collagen fibers to surrounding structures during immobilization following trauma or as a adrenalscomplication of surgery which restricts normal elasticity of the structures involved.

ADRENAL GLANDS - Each adrenal gland is about the size of the thumb and sits atop each kidney. The outer part of the gland is called the cortex. It produces steroid hormones such as cortisol, aldosterone, and testosterone. The inner part of the gland is called the medulla. It produces epinephrine and norepinephrine, which are also called adrenaline and noradrenaline, which are the primary neurotransmitters involved in the sympathetic nervous system.

ADRENALIN - more correctly known as epinephrine, a primary neurotransmitter in the sympathetic nervous system.

ADRENERGIC - Referring to substances which stimulate the sympathetic nervous system, aka sympathomimetic.

ADRENERGIC BLOCKING AGENT - A substance that blocks responses to sympathetic nerve stimulants, more correctly known as an adrenergic antagonist.

AFEBRILE - Without fever; usually refers to a patient whose temperature is normal. affinities

AFFINITY (DRUG) - A drug's affinity refers to its adherence to a receptor, whether or not a biological response is elicited. It is common for an antagonist to have a high receptor affinity, although the action of an agonist is blocked by this.

AGLUTITION - Difficulty in swallowing.

AGNOSIA - the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss.

AGONIST - a drug which acts similarly to a reference drug, often endogenous; interacts with the same agonist spectrumreceptor. For instance, oxycodone is a "pure μ-agonist", meaning that it interacts with the opioid receptor most responsible for pain reduction, euphoria, etc. It also means that (in theory at least) there is no ceiling to its dose; i.e., the response continues as the dose is increased, regardless of history with the drug. The graphic shows the continuum of different agonist activities. Compare with antagonist.

AGONY - Extreme pain.

AKINESTHESIA - Loss of sense of movement, as in a muscle.

ALCOHOL - usually refers to ethanol, the least toxic of the simple alcohols; the family includes methyl (wood) alcohol and isopropyl (rubbing) alcohol. Was used for chemical sympathectomies in the treatment of CRPS pain, but this practice has fallen out of favor since it is common for the pain to return with a vengeance. About 72% of Americans drink alcohol.alcoholism

ALCOHOLISM - Alcoholism, or the severe dependency upon alcohol and the inability to stop drinking once one has started, has been, in the last 30 years or so, recognized as a primary disease. Its two major symptoms are loss of control once drinking has begun, and denial that the person has an alcohol problem, even in the face of irrefutable evidence. Denial is an important part of the syndrome, since not to deny the problems with alcohol would mean that the person would have to face and deal with them.

ALGESIC - Painful.

alkaloidsALGOLOGY - The science and study of pain phenomena. An algologist is a student, investigator, or practitioner of algology.

ALKALOID - Not used much any more; generally means a natural product which is basic, usually due to the presence of one or more nitrogen atoms in the structure.

ALLERGIC REACTION - A reaction to foreign substances (allergens) by the body’s immune system. Substances that trigger allergies include pollen, dust mites, animal fur, some medications, and certain foods.allodynia

ALLODYNIA - Extreme pain is produced by any stimuli that would not normally induce pain (such as touch, pressure and warmth).

ALLOSTERIC MODULATOR - A drug that binds to a receptor at a site distinct from the active site. Induces a conformational change in the receptor, which alters the affinity of the receptor for the endogenous ligand. Positive allosteric modulators increase the affinity, while negative allosteric modulators decrease the affinity.

ALPRAZOLAM - aka Xanax, the most commonly prescribed benzodiazepine in the country. Can be seriously Alzheimer brainaddicting, and is the only benzo known so far whose withdrawal syndrome can be fatal.

ALZHEIMER'S DISEASE - a progressive neurologic disease of the brain that leads to the irreversible loss of neurons, brain material, and dementia.

AMBULATORY - Not bedridden, able to walk by oneself.

amino acidsAMBULATORY SURGERY - Surgery performed either in a special ambulatory care unit or doctor's office. Outpatient surgery.

AMINO ACID - one of 20 small organic molecules which form the building blocks for polypeptides, or proteins. Nine are "essential", meaning that they must come from the diet since the body cannot synthesize them from other molecules.Elavil

AMITRIPTYLINE - a tricyclic antidepressant (TCA) often used in initial pain Tx - Elavil®. Known for being a "dirty drug" - one that has many uncomfortable side-effects, in this case due to its strong anticholinergic properties.

amphetamineAMPHETAMINE - a class of drugs that stimulate the sympathetic nervous system (and thus are sympathomimetic), and can be very addictive. Representative drugs include amphetamine (Adderall®), methamphetamine (Desoxyn®), MDA, MDMA ("ecstasy", "X"), and several others. Ritalin® (methylphenidate, aka Focalin® [single optical isomer]) is not an amphetamine, but is a stimulant nonetheless.

AMPUTATION - The surgical removal of a limb or part of a limb.

ALSAMYOTONIA - Absence of muscle tone.

AMYOTROPHIC LATERAL SCLEROSIS (ALS) - a serious neurological disease that causes muscle weakness, disability and eventually death. ALS is often called Lou Gehrig's disease, after the famous baseball player who died of it in 1941.

ANALGESIA - Absence of pain in response to stimulation that would normally be painful.

ANALGESIC DRUG - Pain-relieving medication such as aspirin, morphine, acetaminophen, etc. It differs from an anesthetic agent in that it relieves pain without loss of consciousness.

ANAPHYLAXIS - a serious allergic reaction that is rapid in onset and may cause death. It typically causes a number of symptoms including an itchy rash, throat swelling, and low blood pressure. Common causes include insect bites and stings, foods, and medications.anemia

ANEMIA - Insufficiency of red blood cells, either in quality or quantity, causing symptoms of low blood oxygen.

ANESTHESIA - Loss of sensation, often produced in order to permit a painless surgical operation. There are actually four stages of anesthesia.

ANESTHESIOLOGIST - A physician who specializes in the administration of anesthesia and in medical procedures that entail the very precise placement of long needles (nerve blocks, etc.).

ANESTHETIC - Drug that is capable of inducing a total or partial loss of sensation, especially tactile sensation and pain. It may act to induce general anesthesia, in which an unconscious state is achieved, or may act locally to induce numbness or lack of sensation at a targeted site.

anginaANGINA PECTORIS - Pain in the chest, sometimes radiating to the left arm, caused by a spasm and/or contraction of the coronary artery of the heart.

ANION - a negatively-charged ion, e.g., I-. Compare with cation.ANKYLOSING SPONDYLITIS

ANKYLOSING SPONDYLITIS - A systemic, inflammatory disease centered in the spine, causing pain and often leading to painful alterations of the vertebral articulations, as well as stiffness of the spine.

ANKYLOSIS - Stiffening or fixation of a joint.

ANOREXIA - the decreased sensation of appetite which may indicate a serious clinical condition. It is a common side effect of many serious diseases such as acute viral hepatitis, AIDS, cancer, congestive heart failure, Crohn's disease, depression, and more.anorexia

ANOREXIA NERVOSA - A mental disorder manifested by extreme fear of becoming obese and an aversion to food, usually occurring in young women and often resulting in life-threatening weight loss, accompanied by a disturbance in body image, hyperactivity, and amenorrhea.

antagonistsANTAGONIST - A drug which blunts or completely halts the effect of another drug, usually by physically blocking the receptor that the drug would ordinarily have occupied. Narcan® (naloxone) is an opioid antagonist, and can reverse an opioid overdose in seconds. Compare with agonist. Can be competitive or non-competitive, each of which can be reversible or irreversible. A competitive antagonist binds to the same site as the agonist but does not activate it, thus blocks the agonist’s action. A non-competitive antagonist binds to an allosteric (non-agonist) site on the receptor to prevent activation of the receptor. A reversible antagonist binds non-covalently to the receptor, therefore can be “washed out”. An irreversible antagonist binds covalently to the receptor and cannot be displaced by either competing ligands or washing.anticholinergic

ANTICHOLINERGIC - the action of a compound that causes antagonism of the NE (norepinephrine) receptors in the body. Since NE is the main neurotransmitter of the sympathetic nervous system, blockage of its receptors causes the drying of most secretory actions, resulting in constipation, drying of the eyes and mouth, blurred vision from lack of tear production, etc. Can be a serious side-effect with serious consequences.

ANODYNE - Any medication that relieves pain. Syn: Analgesic Drug.

ANTICONVULSANT - An agent that prevents or relieves convulsions. Can also be used to treat chronic pain in certain circumstances.

ANTIDEPRESSANT MEDICATIONS - Those that aid in combating the disease of depression, which can be endogenous (innate, often genetically linked) or situational (in response to factors in one's life). Tx is similar for both varieties. Families are named by their pharmacology, e.g., SSRI = Selective Serotonin Reuptake Inhibitor. The goal is to increase the amount of brain neurotransmitters serotonin and/or norepinephrine, deficits of which are associated with depressive symptoms. Can also be used to treat chronic pain in certain circumstances.

ANTI-INFLAMMATORY DRUGS - Medication which is used to reduce inflammation. May be a steroid or ‘non-steroidal’.

ANTINOCICEPTIVE - lacks the ability to transmit, or blocks, nociceptive pain signals; often applied as an adjective to describe the action of a drug.

ANTIPSYCHOTIC - A drug class that acts to reduce the core symptoms of psychosis, most usually schizophrenia. The prototype drug group is the phenothiazines (e.g., chlorpromazine, aka Thorazine®); there are now many varieties and drug classes.anxiety

ANXIETY - An unpleasant emotional state consisting of psychophysiological responses to anticipation of unreal or imagined danger, ostensibly resulting from unrecognized intrapsychic conflict. Physiological concomitants include increased heart rate, altered respiration rate, sweating, trembling, weakness, and fatigue; psychological concomitants include feelings of impending danger, powerlessness, apprehension, and tension. Typically treated with benzodiazepines.

ANXIOLYTIC - Medication used to treat anxiety, and also used to treat chronic pain. Anxiolytics reduce pain-related anxiety, help relax muscles and can help a person cope with pain.

APHASIA - a collection of language disorders caused by damage to the brain. The difficulties of people with aphasia can range from occasional trouble finding words to losing the ability to speak, read, or write, but does not affect intelligence.

APNEA - A temporary stopping of breathing, often occurring during sleep.

arachnoiditisAPRAXIA - a motor disorder caused by damage to the brain, in which someone has difficulty with the motor planning to perform tasks or movements when asked, provided that the request or command is understood and he/she is willing to perform the task. Apraxia is an acquired disorder of motor planning, but is not caused by incoordination, sensory loss, or failure to comprehend simple commands (which can be tested by asking the person to recognize the correct movement from a series).

ARACHNOIDITIS - An inflammation of the arachnoid, the protective membrane that covers the brain and spinal cord. Although this condition has no consistent symptom patterns, it commonly affects the nerves connecting the lower back and the legs. Arachnoiditis is characterized by chronic pain, tingling, numbness, muscle spasms and uncontrollable twitching. Additionally, the condition often brings about neurological problems and severe "electric shock"-like sensations.arrhythmia

ARRHYTHMIA - Lack of rhythm, applied especially to irregularities of heart beat.

arthritisARTHRITIS - Inflammation of one or more joints, which results in pain, swelling, stiffness, and limited movement. There are more than 100 different types of arthritis; the two major types are osteoarthritis and rheumatoid arthritis. Common symptoms include: joint pain, joint swelling, reduced ability to move the joint, redness of the skin around a joint, stiffness, especially in the morning, and warmth around a joint.arthroscopy

joint articulationARTHROSCOPY - A procedure wherein an orthopedist looks into a joint with a specially-designed lighted hollow instrument.

ARTICULATION - a joint, or the place at which two or more bones join each other. Nearly all articulations allow for movement of the joined bones.

ASTHMA - There are two types of asthma: restrictive and inflammative. The medicines prescribed for asthma are bronchodilators, which release asthmathe restrictive forces of restrictive asthma, and corticosteroids to ease inflammations of the inflammatory type.

ASYMPTOMATIC - Without symptoms. Usually refers to someone who previously did have symptoms.

ATROPHY - The withering of an organ or tissues which had previously been normally developed due to degeneration of cells. This may be due to disease, aging or malnutrition.

AURA - A symptom that heralds the onset of a migraine headache or a seizure. Typically, auras are visual phenomena, but they autoimmune diseasemay include any sensation or behavioral change that occurs shortly before the onset of the headache or seizure.

AUTOIMMUNE DISEASE - Autoimmune diseases are any diseases whereby the body suddenly doesn't recognize a part of itself and develops antibodies to fight it, kill it and destroy it. They are strange in their origins; some are neurological and others are genetic mutations wired into the cells of the body's DNA prior to birth and surface at a specific time or when a given set of conditions "unlocks" the directions for the body to turn on an autoimmune defense.autonomic nervous system

AUTONOMIC NERVOUS SYSTEM - The portion of the nervous system over which there are no voluntary, conscious control, including heart beat, breathing, intestinal movements, sweating, etc. Subdivided into the sympathetic and parasympathetic nervous systems.

- a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present. It is usually performed by a specialized medical doctor called a pathologist.

AXON - Nerve fiber that is capable of rapidly conducting impulses away from the neuron cell body.



BACTEREMIA - The presence of bacteria in the bloodstream, as indicated by a true-positive blood culture result.

BACTERIA - Unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and Baker's cystexhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal.

BACTERIOCIDE - a compound or mixture that is toxic to bacteria.

BAKER'S CYST - Localized swelling of a bursa sac in the posterior knee as a result of fluid that has escaped from the knee capsule. A Baker's cyst indicates that there is a trauma inside the knee joint that leads to excessive fluid production.

barbituratesBARBITURATE - a class of sedative/hypnotics that has been available for over 50 years; examples include sodium pentobarbital, phenobarbital, secobarbital, and others. Most are C-II, and have been generally replaced by benzodiazepines, since barbiturates are so easy to OD on; suicides using these drugs used to be common, especially when mixed with alcohol. Were commonly used in state-sanctioned murders as part of the three-component lethal drug mixture, until European manufacturers refused to ship the products for uses such as taking a human life.Basal Ganglia

BASAL GANGLIA - group of structures which coordinate movement; located in the forebrain (telencephalon).

BENIGN - Not malignant; not recurrent; favorable for recovery.

diazepamBENZODIAZEPINE - a class of minor tranquilizers discovered serendipitously in 1962. The first was chlordiazepoxide (Librium®), followed quickly by diazepam (Valium®; see diagram to left), alprazolam (Xanax®), clonazepam (Klonopin®), and many more. First believed to be and advertised as non-addictive, we now know that these drugs can be very addictive, especially the long half-life analogs like diazepam. Known colloquially as "benzos" (including among docs).

BEREAVEMENT - The act of grieving someone's death.

BETA BLOCKER - Drug that tends to slow the heart rate and the force of heart contractions to lower the blood pressure.

BIAS - A systematic error in the design, conduct, or interpretation of a study that may cause a systematic deviation from the underlying truth (e.g., overestimation of a treatment effect because of failure to randomize).

BINDING SITE - The portion of the receptor to which a ligand (neurotransmitter, drug) actually adheres to. Binding can be based binding site upon weak and/or strong bonds that are formed between the ligand and the binding site. Occupancy of the binding site can lead to a chain of events that culminate in an effect. However, occupancy does not imply an effect since antagonists can bind but produce no direct effect as a result of occupancy.

bioavailabilityBIOAVAILABILITY - Also referred to as availability, this is the amount of a drug that is absorbed into circulation after administration of a specific dosage.

BIOEQUIVALENCE - Drugs that are bioequivalent provide the same amount of active drug to the body. This term is used when comparing the same drug manufactured by two companies, or two different preparations (e.g. oral vs. im).biofeedback

BIOFEEDBACK - Giving information to an individual, through visual or auditory means, on the state of certain physiological responses such as heart rate, etc.) so that the individual can gain some voluntary control over these procedures.

biotransformationBIOTRANSFORMATION - The chemical change of a drug that happens due to the effects the body has on it. Pharmacodynamics involves the chemical effects of a drug on the body; biotransformation involves the chemical effect of the body (primarily the liver) on a drug. “Biotransformation” should be used in preference to “drug metabolism”, and the word “metabolism” should probably be reserved to denote the biotransformation of materials essential to an adequate nutritional state. “Biotransformation” and “detoxication” are not synonyms: the product of a biotransformation may be more, not less, biologically active, or potent, than the starting material.bipolar

BIPOLAR DISORDER - a mental illness in which the patient alternates between periods of energy and euphoria (manic phase) and times of deep depression and lack of energy (depressive phase). It is treated with a variety of drugs, the first successful of which was lithium carbonate (Li2CO3).

BLIND EXPERIMENT - A type of experiment in which the participants are unaware of the drug doses or treatments involved, so as not to affect the outcome. In a “single-blind” experiment, one participant – usually the subject – is left uninformed. In a “double-blind” experiment two participants – usually the subject and observer – are uninformed, and in a “triple-blind” experiment the subject, the observer, and the person responsible for the actual administration of the drug are left unaware of the nature of the material administered.blood-brain barrier

BLOOD-BRAIN BARRIER - the very selective, permeable membrane separating the circulating blood from the cerebrospinal fluid (CSF) that surrounds the spinal cord and brain. The membrane is almost impermeable to ionic or inorganic substances, while lipophilic compounds tend to cross easily.

BODY IMAGE - A person’s perception of his/her physical body.

bone scanBONE DEOSSIFICATION - Demineralization of bone, see also osteopenia.

BONE SCAN - A process used to check for the presence of damage or changes in the bones which enables them to be seen long before they become visible on an ordinary X-ray. Although they can sometimes show the presence of RSD, they do not always successfully detect it. The triphasic bone scan is one of the best ways to diagnose RSD; the best description is in an online textbook on orthopedics. Please click the image to see the original.

BOOLEAN OPERATORS - Words used when searching electronic databases. These operators are AND, OR, and NOT and are used to combine terms (AND/OR) or exclude terms (NOT) from the search strategy.

BOUND - This term is used to refer to the binding of a drug or other compound or element to another molecule or element. Typically, the "bound" fraction of a drug has certain characteristics. For example, protein binding of a drug limits the amount of free drug available to induce an effect. Receptor binding of a drug can elicit a chain of events leading to an effect. Binding to an enzyme may increase or decrease enzyme activity. In most cases, the fraction bound to a receptor or an enzyme is considered to be very small relative to the fraction that is not bound. On the other hand, the amount of drug bound to plasma proteins can be considerable (e.g., 90%).

BOWEL - The large intestine, which is part of the gastrointestinal (GI, digestive) system in the body.

BRACHYTHERAPY - A type of radiotherapy in which the source of radiation is placed (or implanted) in or close to the area being treated.

BRAIN DEATH - The irreversible cessation of all functions of the entire brain, including the brainstem.
Brawny Edema

BRAWNY EDEMA - Thickening and dusky discoloration of edematous tissue.

BREAKTHROUGH PAIN - A short-term flare of pain of moderate to severe intensity occurring against a background of otherwise controlled pain. Often caused by physical or emotional stress.

BRIEF FATIGUE INVENTORY - A fatigue assessment tool that asks patients to rate, on a scale of 0 (none) to 10 (severe), their current level of fatigue, usual fatigue level in the last 24 hours, worst level of fatigue in the last 24 hours, and how fatigue has interfered with general activity, mood, walking, work, relationships, and enjoyment of life.

BRIEF PAIN INVENTORY - A pain assessment tool that asks patients whether they have any pain now and, if so, where it is located; to rate, on a scale of 0 (none) to 10 (severe) their level of pain in the last 24 hours (worst, least, average); current level of pain; treatments for pain and how much they have relieved the pain; and how pain has interfered with general activity, mood, walking, work, relationships, and enjoyment of life.

bromineBROMINE - one of the halogen elements, used in the preparation of many drugs. A diatomic molecule (Br2), the heavy, dark red liquid fumes on contact with air and is extremely dangerous to breathe or get on skin.

BULIMIA - Bulimia nervosa, known simply as bulimia, is an eating disorder that typically consists of binging and purging. bulimiaHowever, the main characteristic is purging. Binging consists of eating very large meals. Purging is forcefully vomiting the meal back up or using a laxative in an effort to satisfy appetite without gaining weight. A very dangerous condition.

bupivacaineBUPIVACAINE - This is an extremely long-acting local anesthetic; its most common brand name is Marcaine®. It is usually the agent of choice for various neural blocks, from epidural to stellate ganglion and many other blocks.

BURNOUT - A form of mental distress manifested in normal individuals by decreased work performance, resulting from negative attitudes and behaviors. In end-of-life care, burnout often results from stresses that arise from the clinician’s interaction with the work environment.

BURSA - A fluid- filled sac that is located in areas where friction is\ likely to occur, then minimizes the friction; for example between a tendon and bone.

BURSITIS - Inflammation of a bursa, occasionally accompanied by a calcific deposit in the underlying supraspinatus tendon; the most common site is the sub-deltoid bursa.


calciumCACHEXIA - any general reduction in vitality and strength of body and mind resulting from a debilitating chronic disease.

CALCIUM - Calcium usually exists as a divalent cation (Ca++). It has important roles in neurotransmission and muscle contraction.cancer

CANCER - also known as a malignant tumor or malignant neoplasm, is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.

cannabidiolCANNABIDIOL (CBD) - one of the main constituents of marijuana (THC (tetrahydrocannabinol) is #1); it is non-psychoactive. Its main activity is as an antispasmodic, for which it is starting to be prescribed as cannabis' legal status continues its climb.

CANNABIS - The hemp plant Cannabis sativa or indica. Products prepared from the dried flowering tops of the plantcannabis include marijuana, hashish, bhang, and ganja.

CARBAMAZEPINE - An anticonvulsant used to control grand mal and psychomotor or focal seizures. Its mode of action is not fully understood, but some of its actions resemble those of phenytoin; although there is little chemical resemblance between the two compounds, their three-dimensional structure is similar.

CARDIAC CACHEXIA - Nonintentional, nonedema weight loss of 7.5% of previous normal weight over a period of 6 months in patients with congestive heart failure or other heart disease.

CARDIOLOGIST - A hospital doctor who is concerned with the diagnosis and treatment of diseases of the heart and blood vessels.

CARDIOPULMONARY RESUSCITATION - An emergency procedure that attempts to to restore normal breathing and/or circulation after respiratory and/or cardiac arrest. Includes clearing the air passages to the lungs, artificial circulation through rhythmic pressing on the patient’s chest, and artificial respiration.

CARDIOVASCULAR - Pertaining to the heart and blood vessels.

Carpal TunnelCAREGIVER - A person who provides direct care to a patient (either at home or in health care settings), whether paid or unpaid.

CARPAL TUNNEL SYNDROME - Numbness, weakness and pain in the hand, involving especially the index, middle and ring fingers, due to cartilagecompression of the medial nerve at the wrist.

CARTILAGE - Smooth, slippery substance preventing two ends of bones from rubbing together and grating.

catecholaminesCATECHOLAMINE - A group of neurotransmitters that are structurally related by a catechol nucleus. They include norepinephrine, epinephrine, and dopamine.

CATHETER - A hollow rubber, plastic, or glass tube for passage into a structure, for the purpose of injecting or removing fluid or blood. Most cathetercommonly used in blood vessels and the urethra.

CATION - a positively-charged ion, e.g., Na+. Compare with anion.

CAT scanCAT SCAN - The acquisition of x-rays from many different depths, thus giving a highly defined, 3D set of pictures of an organ or organs. Also called a CAT Scan or Computed Axial Tomography (thus its CAT acronym).

CAUDA EQUINA - The "tail" end of the spinal cord composed of the nerves which proceed to the lower part of the trunk and lower extremities.

CAUSALGIA - A burning sensation in the palms, soles or digits, originally thought to be due to irritation or disease in the nerves supplying these areas. It's now known that this was the first name given to CRPS/RSD.

cell membraneCELL MEMBRANE - (also known as the plasma membrane or cytoplasmic membrane) is a biological membrane that separates the interior of all cells from the outside environment. Its main feature is a lipid bilayer, comprised of long molecules with a hydrophilic head and lipophilic tail, the latter of which points toward the inner part of the membrane.

CENTRAL DOPAMINE TYPE 2 (D2) RECEPTOR - Dopamine receptors that control neural signaling modulating many important behaviors, such as spatial working memory. Opioid-induced nausea and vomiting are caused by their effects in the chemoreceptor trigger zone that are largely mediated through central D2 receptors, whereas opioid effects on the stomach producing gastroparesis are mediated through peripheral D2 receptors. central nervous system

CENTRAL NERVOUS SYSTEM (CNS) - the part of the nervous system consisting of the brain and spinal cord. So named because it integrates information it receives from, and coordinates and influences the activity of, all parts of the bodies of bilaterally symmetric animals, and it contains the majority of the nervous system. The remainder of the nervous system is called the peripheral nervous system.

CENTRAL PAIN - Pain associated with a lesion of the central nervous system, or which permeates the CNS due to central sensitization.

CENTRAL SENSITIZATION - a condition of body-wide allodynia or hyperalgesia, which can precede whole-body RSD. Can be thought of as the CNS being on high alert, in which various stimuli can cause an over-reaction and great pain.

CENTRAL VENOUS CATHETER - A hollow plastic tube inserted into a vein in the arm or neck, and pushed forward until it reaches the vena cava in the chest. It is often used for giving medication.

CEREBELLUM - Part of the metencephalon that lies in the posterior cranial fossa behind the brain stem. It is concerned with the coordination of movement.

CEREBRAL HEMORRHAGE - Bleeding into the brain tissue from a ruptured blood vessel, also known as a hemorrhagic stroke. It can cause abrupt dysfunction of neurologic tissue, leading to neurologic deficits such as hemiparesis, hemisensory loss, aphasia, ophthalmoplegia, and visual field cuts.

CEREBRAL PALSY - a group of non-progressive and non-contagious motor conditions that cause physical disability in human development. Cerebral palsy primarily effects various areas of bodily movement.

CEREBROSPINAL FLUID (CSF) - The odorless, colorless fluid that surrounds the brain, spinal cord, and all other components to the central nervous system (CNS). Click the diagram on the right to see the anatomical features involved in CSF production and circulation. It provides a controlled, sterile environment for the CNS, carrying nutrients to the system among other vital functions. Occasionally collected via a spinal tap for diagnostic purposes.

CERVICAL - Pertaining to the neck, or to the neck of any organ or structure.

CHAKRAS - energy points or nodes in the subtle body. Chakras are part of the subtle body, not the physical body, and as such are the meeting points of the subtle (non-physical) energy channels called nadiis.

CHEMORECEPTOR TRIGGER ZONE (CTZ) - Functionally outside the blood-brain barrier, the chemoreceptor trigger zone is exposed to toxins in the bloodstream and cerebrospinal fluid that can stimulate vomiting.

CHEYNE-STOKES RESPIRATIONS - A rhythmic waxing and waning of both respiratory pattern rate and tidal volumes that includes regular periods of apnea.

CHIROPODIST - A person who is concerned with chiropody, which is the study and care of the foot.

CHIROPRACTIC - A system of diagnosis and treatment based on the concept that the nervous system coordinates all of the body's functions, and that disease results from a lack of normal nerve function. Chiropractic medicine uses manipulation and adjustment of body structures, such as the spine, to relieve pressure on nerves coming from the spinal cord.

CHIROPRACTOR - One who treats disease by a system of healing which employs manipulation and specific adjustment of body structures (primarily the spine).

CHLORINE - one of the halogen elements, used in the preparation of, and is part of, many drugs. A diatomic molecule (Cl2), the heavy, green-yellow gas was the first gas used for chemical warfare during WWI. When inhaled, chlorine reacts with water in the lungs to produce one mole each of hypochlorous acid and hydrochloric acid: Cl2 + H2O ----> HO-Cl + HCl. The liberated HCl causes fluid accumulation and pulmonary edema, which can cause death rapidly.

CHOLESTEROL - The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Dietary restrictions on cholesterol were just removed, due to new evidence that dietary sources of cholesterol have little bearing on serum cholesterol levels.

CHOLINERGIC - Refers to biological systems that rely on acetylcholine as a neurotransmitter. There are two fundamental neuropharmacologic types of cholinergic neurons: nicotinic and muscarinic. There are three basic anatomic divisions of cholinergic neurons: neuromuscular, ganglionic and post-ganglionic.

CHONDRITIS - Inflammation of cartilage.

CHROMOSOME - Self-replicating structures in the nucleus of a cell that carry the genetic information.

CHRONIC - Effects from a syndrome, illness, etc. lasting of long duration, usually several months to a year or more. Compare with acute.

CHRONIC FATIGUE - Fatigue present in an individual at least 50% of the time that persists for at least 6 months.

CHRONIC FATIGUE SYNDROME (CFS) - An illness predominantly affecting young adults and characterized by disabling fatigue of at least 6 months’ duration, accompanied by several other symptoms (such as sore throat, adenopathy, muscle pain, multijoint pain, and headache) that cannot be attributed to any alternative condition.

CHRONIC PAIN - a state in which pain persists beyond the usual course of an acute disease or healing of an injury, or that may or may not be associated with an acute or chronic pathologic process that causes continuous or intermittent pain over months or years.

CHRONIC RENAL FAILURE - a condition that results in the progressive loss in renal function of a period of months or years. Often, chronic renal failure is diagnosed as a result of screening of individuals who are known to be at a risk for kidney problems, such as those who suffer from high blood pressure, diabetes or those whose blood type is relative with chronic kidney disease.

CIRRHOSIS - Widespread disruption of normal liver structure by fibrosis and the formation of regenerative nodules that is caused by various chronic progressive conditions affecting the liver (such as long-term alcohol abuse or hepatitis).

CLEARANCE - of a chemical is the volume of body fluid from which the chemical is, apparently, completely removed by biotransformation and/or excretion, per unit time. In fact, the chemical is only partially removed from each unit volume of the total volume in which it is dissolved.

CLINICAL PRACTICE GUIDELINES - A strategy for changing clinician behavior. Systematically developed statements or recommendations to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances. They present indications for performing a test, procedure, or intervention, or the proper management for specific clinical problems. Guidelines may be developed by government agencies, institutions, organizations such as professional societies or governing boards, or by convening expert panels.

CLINICAL TRIAL - a tightly controlled, statistically valid test of a drug's efficacy, compared to a placebo. In the US, there are three phases of clinical trials, using progressively larger test populations with increasing number if ill patients. For instance, Phase I trials are done with healthy volunteers, to look for undesirable side-effects, optimize dosing protocols, and establish PK/PD data.

CLUSTER HEADACHE - A chronic headache condition, also called migrainous neuralgia.

CNS - central nervous system - the part of the nervous system consisting of the brain and spinal cord.

COCAINE - An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.

CODE OF MEDICAL ETHICS - The American Medical Association's Code of Medical Ethics is an ethics guide for practicing physicians that is reviewed and updated over time.

CODEINE - An opioid analgesic related to morphine but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough. The majority of morphine in the US is used for conversion to codeine.

COGNITION DISORDER - Disorders such as dementia and delirium that involve mental activities associated with thinking, learning, and memory.

COGNITIVE - Relating to the process of knowing or being aware. Cognition includes thinking, learning and judging.

COHORT STUDY - Study of a group of individuals, some of whom are exposed to a variable of interest (e.g., a drug treatment or environmental exposure), in which participants are followed up over time to determine who develops the outcome of interest and whether the outcome is associated with the exposure.

COLITIS - swelling/inflammation of the colon. It has a number of possible causes, so it is essentially a symptom rather than an illness, though it causes distinct symptoms of its own. It can also be considered an illness if it is chronic and there is no known underlying cause.

COLLAGEN - the main structural protein in connective tissue, and is the most prevalent protein in the body. It is the main material making up ligaments, tendons, and some parts of the skin. As we age, collagen is depleted, giving rise to wrinkles, sagging skin, etc.

COMORBIDITY - Disease(s) or conditions that coexist(s) in study participants in addition to the index condition that is the subject of the study.

COMPARTMENT SYNDROME - a medical emergency that involves increased pressure in a muscle compartment. It can lead to muscle and nerve damage and problems with blood flow, and has been known to precipitate CRPS. Fascia do not expand. Any swelling in a compartment will lead to increased pressure in that area, which will press on the muscles, blood vessels, and nerves. If this pressure is high enough, blood flow to the compartment will be blocked. This can lead to permanent injury to the muscle and nerves. If the pressure lasts long enough, the muscles may die and the limb may need to be amputated. Cf. rhabdomyolysis.

COMPENSATION CASE - An injury or disease incurred because of the work one performs; refers to the involvement of Workers Compensation insurance and its associated laws and guidelines.

COMPLEMENTARY AND ALTERNATIVE MEDICINE (CAM) - the term for medical products and practices that are not part of standard care. Standard care is what medical doctors, doctors of osteopathy and allied health professionals, such as registered nurses and physical therapists, practice. Alternative medicine means treatments that you use instead of standard ones. Complementary medicine means nonstandard treatments that you use along with standard ones. Examples of the many CAM therapies include acupuncture, low-level laser therapy, meditation, aroma therapy, Chinese medicine, dance therapy, music therapy, massage, herbalism, therapeutic touch, yoga, osteopathy, chiropractic treatments, naturopathy, and homeopathy.

COMPLEX REGIONAL PAIN SYNDROME (CRPS) - a complicated, multifaceted illness centered in the CNS; the most painful medical condition known. There is no organ or body location that has been shown to be immune to invasion by CRPS, and the syndrome usually becomes chronic. Earlier known as reflex sympathetic dystrophy (RSD), and, before that, causalgia. CRPS usually starts in the foot or hand after an injury, such as a broken bone, or nerve damage from surgery. The main symptom is extreme pain – often described as burning. Other symptoms can include sensitivity to touch, skin changes, swelling, weakness and loss of movement in the hand or foot.

CONDUCTION - The transfer of sound waves, heat, nervous impulses, or electricity.

CONFLICT OF INTEREST - A situation in which an individual or group is involved in multiple interests (concerns), and one or more interests could possibly affect the motivation for an action or interpretation regarding another interest. Also, within the biomedical research and publishing enterprise, these conflicts may occur when investigators, authors, institutions, reviewers, and/or editors have financial or nonfinancial relationships with other persons or organizations (e.g., study sponsors) or personal investments in research projects or the outcomes of projects that may inappropriately influence their interpretation or actions. Conflicts of interest can lead to biased design, conduct, analysis, and interpretation of study results.

CONGENITAL - Existing before birth; to be born with.

CONGESTIVE HEART FAILURE - a syndrome of ventricular dysfunction. Left ventricular failure causes shortness of breath and fatigue, and right ventricular failure causes peripheral and abdominal fluid accumulation; the ventricles can be involved together or separately. Treatment includes patient education, diuretics, ACE inhibitors, angiotensin II receptor blockers, β-blockers, aldosterone antagonists, digitalis, specialized implantable pacemakers and other devices, and correction of the underlying disorder.

CONJUNCTIVITIS - occurs when the eyelid lining swells, which can happen for a number of reasons. These include infection, disease, parasites and allergies. Some sexually transmitted diseases can also cause conjunctivitis. Conjunctivitis is closely related and often referred to as "pink eye," which is essentially the same symptoms caused by a viral infection in the conjunctiva (eyelid lining).

CONNECTIVE TISSUE DISORDER - A group of diseases including rheumatoid arthritis, systemic lupus erythematosus, rheumatic fever, scleroderma and other disorders, that are sometimes referred to as rheumatic diseases. They probably do not affect solely connective tissues but the diseases are linked in various ways and have interesting immunological features which suggest that they may be autoimmune in origin.

CONSCIOUS SEDATION - Administering sedatives with or without analgesics to induce a mildly sedated state (“twilight sleep”) that allows the patient to tolerate unpleasant procedures while avoiding the need for intubation and mechanical ventilation.

CONSTIPATION - the inability to pass stool or difficulty having a bowel movement. It is also defined as not passing stool at least three times per week. Millions of people suffer from constipation in the United States every year and it is more likely to affect women. People who are elderly, pregnant or have recently had surgery may also develop constipation.

CONTINUOUS INFUSION - In the test for intrathecal drug delivery, the slow introduction of the test pain-relieving medicine into the intrathecal space surrounding the spinal cord over a period of time.

CONTRACTURE - The shortening of a muscle, tendon or other structure so that it can not be straightened or readily flexed and extended. Scar tissue often results in contractures, which are often very painful.

CONTROLLED SUBSTANCE - a chemical placed in one of the five schedules of the Controlled Substances Act (C-I through C-V), promulgated in 1970 at the start of Nixon's infamous "War on Drugs". The graphic to the left is the official seal of a drug in Schedule II; the others replace the "II" with the appropriate Roman numeral I - V. For a short table of the schedules and representative drugs, please click here.

CONTUSION - injury to tissues without breakage of skin; a bruise. In a contusion, blood from the broken vessels accumulates in surrounding tissues, producing pain, swelling, and tenderness. A discoloration appears as a result of blood seepage under the surface of the skin.

CONVULSION - a medical condition where body muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body.

CORONARY - Encircling in the manner of a crown; a term applied to vessels; nerves, ligaments, etc. The term usually denotes the arteries that supply the heart muscle and, by extension, a pathologic involvement of them.

CORTEX - The outer layer of an organ or other body structure, as distinguished from the internal substance.

CORTISOL - a steroid hormone, more specifically a glucocorticoid, which is produced by the adrenal cortex. It is released in response to stress and a low level of blood glucose.

COSTOCHONDRITIS - Inflammation and pain in the area where the cartilages join the breastbone (sternum).

COVALENT BOND - a bond between two atoms in which the outermost ("valence") electrons are shared (as opposed to an ionic bond, where an electron is transferred from one atom to another to create ions). Depending on how equitably the electrons are shared, one of the atoms can have a partial charge (δ+ vs. δ-) relative to the other atom; this occurs when the electronegativity difference between the two atoms is significant.

CROHN'S DISEASE - An ulcerative condition of the small and large bowel.

CROSSOVER EXPERIMENT - A type of experiment in which each participant receives a trial preparation. The preparations are then crossed between participants in order to calculate the effects of the trial preparations through various participants.

CRYESTHESIA - Sensitivity to cold.

CRYMODYNIA - Pain which comes on in cold or damp weather. Common in those who suffer from arthritis and other pain disorders.

CRYOANALGESIA - A semi-permanent nerve blocking technique where nerves are destroyed with extreme cold to relieve pain for weeks or months.

CSF - see cerebrospinal fluid.

CUBITAL - Referring to the forearm or elbow area.

CYANOTIC - Bluish color of the skin and mucous membranes, usually due to poor circulation and insufficient oxygen in the bloodstream.

CYST - Any closed cavity or sac; normal or abnormal, lined by epithelium, and especially one that contains a liquid or semisolid material.

CYSTIC FIBROSIS - a genetic disorder that affects secretions of the body. Its primary symptom is a production of mucus that is thicker than mucus in individuals without the disease. The mucus causes potentially fatal problems in the respiratory and digestive systems.

CYTOKINES - A family of small non-antibody proteins that are involved in cell signaling. They are important in health and disease, specifically in host responses to infection, immune responses, inflammation, trauma, sepsis, cancer, and reproduction (from Wikipedia article).

Quick links to other letters


DEAFFERENTATION PAIN - Pain due to loss of sensory input into the central nervous system, as occurs with avulsion of the brachial plexus or other types of lesions of peripheral nerves or due to pathology of the central nervous system.

DEEP HEAT THERAPY - The use of heat to treat certain medical conditions including chronic pain with products such as heat packs, paraffin baths and radiant heat, or with a hot bath or towels immersed in hot water. Diathermy is a type of deep heat therapy.

DEFIBRILLATOR - An electrical device used to reverse an abnormal heart rhythm and re-start a heart, for example following a heart attack, by applying a brief electric shock.

DEGENERATIVE - Undergoing degeneration: tending to degenerate; having the character of or involving degeneration; causing or tending to cause degeneration.

DEGENERATIVE DISK DISEASE - A disease affecting the spine, specifically the spinal discs, the soft cushions that sit between each vertebra of the spine. Degenerative disc disease can cause chronic pain.

DELIRIUM - A disturbance of the brain function that causes confusion and changes in alertness, attention, thinking and reasoning, memory, emotions, sleeping patterns and coordination. These symptoms may start suddenly, are due to some type of medical problem, and they may get worse or better multiple times.

DELERIUM, HYPERACTIVE - Delirium commonly characterized by restlessness, agitation, hypervigilance, hallucinations, and delusions.

DELERIUM, HYPOACTIVE - Delirium that includes psychomotor retardation, lethargy, and reduced awareness of surroundings. It is often mistaken for depression and is difficult to differentiate from sedation because of opioids or obtundation in the last days of life.

DELIRIUM TREMENS - occurs most commonly in individuals who have been drinking alcohol daily for a prolonged period. It is a symptom of alcohol withdrawal that is nearly synonymous with alcohol cessation. Please note that delirium tremens is a medical emergency. If you or someone you know is suffering from delirium tremens, seek medical attention immediately.  The symptoms of delirium tremens are more severe than most drug withdrawal symptoms and can lead to death.

DELTA (Δ) OPIOID RECEPTOR - One of the three opioid receptor subtypes; its actions include analgesia, antidepressant & convulsant action, and physical dependence.

DEMENTIA - A progressive condition marked by development of multiple cognitive deficits that include memory impairment and at least 1 of the following cognitive disturbances: agnosia, aphasia, apraxia, or a disturbance in executive functioning.

DENERVATE - To cut a nerve going to or from an organ or structure. This is sometimes done surgically to relieve pain.

DEPENDENCE (DRUG) - currently used synonymously with addiction.

DEPRESSION - A mental state of depressed mood characterized by feelings of sadness, despair, discouragement, inability to concentrate, insomnia, and feelings of rejection and guilt.

DERMATOLOGY - A medical specialty concerned with the skin, its structure, functions, diseases, and treatment.

DERMATOMYOSITIS - a muscle disease characterized by inflammation and a skin rash, which may appear over the face, knuckles, neck, shoulders, upper chest, and back. It is a type of inflammatory myopathy. Symptoms include: difficulty swallowing, muscle weakness, stiffness, or soreness, purple or violet colored upper eyelids, purple-red skin rash and shortness of breath.

DESENSITIZATION - The prevention or reduction of immediate hypersensitivity reactions by administration of graded doses of allergen; called also hyposensitization and immunotherapy. Often applied to a technique for lessening allodynia, in which materials of increasing coarseness are rubbed across the affected area. If the patient can tolerate it, it's quite effective.

DIABETES - A chronic disease associated with abnormally high levels of sugar in the blood. A common cause of peripheral nerve damage, as well as other irreversible consequences.

DIABETIC NEUROPATHY - Numbness of pain and weakness in the hands, arms, feet or legs caused by the effects of diabetes on the nerves. Diabetes may cause nerve problems in every organ system.dialysis

DIALYSIS - A medical procedure used in a patient with renal failure to remove wastes or toxins from the blood and to adjust fluid and electrolyte imbalances by using a semipermeable membrane.

DIARRHEA - an increase in the frequency of bowel movements or a decrease in the form of stool, characterized by unusually frequent bowel movements and excessive watery evacuations of fecal material. Persistent diarrhea can cause dehydration, can indicate an underlying infection, or it may mean that the body is not able to absorb some nutrients due to a problem in the bowels.

DIASTOLIC PRESSURE - The blood pressure level during the time the heart muscle is relaxed. It's the lower number in a b.p. reading, so for 120/80, the diastolic pressure is 80. The upper number is the systolic pressure, when the heart's ventricles are fully contracted and thus the pressure is the highest.

DIATHERMY - A technique that uses high-frequency electrical currents to heat deep muscular tissues to increase blood flow and speed up recovery.

DIAZEPAM - The first brand name was "Valium", and for several years in the mid-1960's, it was the #1 prescribed drug in the country. Known as a "minor tranquilizer", and initially advertised as being non-addictive, diazepam is used for anxiety, phobias, panic attacks, insomnia, and similar psychiatric problems. Its very long half-life (~96 hrs) make it in fact quite addictive, even at therapeutic doses.

DILAUDID® - hydromorphone, a very strong, C-II opioid which is synthesized from thebaine, a constituent of poppy straw.

DISEASE - A disturbance in the body or function of an organ or organs.

DYSPEPSIA - Indigestion. Functional dyspepsia is pain or discomfort centered in the epigastrium with a normal endoscopy.

DYSPHAGIA - Difficulty in swallowing.

DYSPNEA - Difficulty breathing or labored breathing.

DYSURIA - Painful urination.

DISTAL - Term referencing one anatomical term away from another, where "distal" means further from the center of the body. For example, the hand is distal to the elbow. The opposite is proximal.

DIVERTICULITIS - characterized by small, bulging sacs, referred to as diverticula, found within the lining of the intestines, that become inflamed and/or infected. In most cases, these inflamed pouches are found in the large intestines where the colon is located.

DOMINANT TRAIT - In genetics, a trait that will appear in the offspring if one of the parents contributes it. Compare with recessive trait.

DO-NOT-RESUSCITATE (DNR) ORDERS - Instructions written by a doctor telling other healthcare providers not to try to restart a patient's heart, using cardiopulmonary resuscitation (CPR) or other related treatments, if his/her heart stops beating. Usually, DNR orders are written after a discussion between a doctor and the patient and/or family members.

DOPAMINE - One of the most important neurotransmitters involved in the nervous system, along with serotonin and norepinephrine. dopamineDysfunction in the dopamine system results in a variety of well-known problems, including Parkinson's disease, ADHD, depression, addiction, and more. Stimulation of the dopamine system is part of the reward system that can lead to addiction, especially to substances but also to behaviors.

DORSAL COLUMN STIMULATOR - Also called a Spinal Cord Stimulator, it is a specialized device, which stimulates or blocks nerve transmission by tiny electrical impulses via small electrical wires placed on the spinal cord.

DORSUM - The back of an organ or body part. Think of the dorsal fin of a shark.

DRUG - In its broadest sense, any substance with a known effect on a biological system. Food items are typically omitted from this definition.

DRUG-RECEPTOR COMPLEX - the association between a drug molecule and the active site of a receptor. D-R complexes have a very specific shape, which causes the generation of an electrical signal that then causes the desired biological effect (e.g., lowering b.p.).

DURABLE POWER OF ATTORNEY FOR HEALTHCARE - A legal document that specifies one or more individuals (called a health care proxy) you would like to make medical decisions for you if you are unable to do so yourself.

Dx - medical shorthand for "diagnosis".

DYSBASIA - Difficulty in walking.

DYSESTHESIA - An unpleasant abnormal sensation, whether spontaneous or evoked.

DYSPHORIA - a feeling of depression, hopelessness, and despair. Its opposite is euphoria.

DYSTHYMIC DISORDER - otherwise known as neurotic depression, dysthymic disorder and chronic depression, is a mood disorder that consists of the same cognitive and physical problems associated with depression. However, dysthymic disorder is less severe but has longer-lasting symptoms that may persist for up to two years. dystonia

DYSTONIA - a neurological movement disorder which causes muscles to spasm and contract involuntarily. Sustained muscle contractions can cause abnormal postures and involuntary repetitive movements. The condition can either be hereditary or can arise from a number of different causes including physical trauma, poisoning, adverse reactions to pharmaceutical drugs or infections.

DYSTROPHY - Abnormal development, progressive changes, and degeneration that may result from a myriad of causes, from CNS diseases to malnutrition of tissue.


EC50 - The concentration of an agonist that produces 50% of the maximum possible response for that agonist. "EC" = "effective concentration".

ECCHYMOSIS - A bruise. A small hemorrhagic spot in the skin or mucous membrane that is larger than a petechia and bluish or purple in color.

ECHOCARDIOGRAPHY (ECG) - A test in which sound waves are directed at the heart. The recordings give important-information on the health of the heart muscles and heart function.

ECTOPIC PREGNANCY - Ectopic pregnancy occurs when a fertilized ovum (embryo) implants in a fallopian tube rather than in the uterus. Less commonly, ectopic pregnancies can occur at sites other than the fallopian tube, such as the cervix, abdomen, ovary, and prior cesarean scar.

ED50 - In vitro or in vivo dose of drug that produces 50% of its maximum response or effect. "ED" = "effective dose".

EDEMA - Excessive accumulation of fluid in the body tissue which causes swelling.

EFFICACY - Describes the way that agonists vary in the response they produce when they occupy the same number of receptors. High efficacy agonists produce their maximal response while occupying a relatively low proportion of the total receptor population. Lower efficacy agonists do not activate receptors to the same degree and may not be able to produce the maximal response

ELECTROCARDIOGRAPHY (EKG) - The recording of the electrical impulses of the heart. Such tracings often give an electrodesaccurate picture of heart abnormalities and disease.

ELECTRODE - A small wire that is attached to the skin or a part of the body, and transmits electronic impulses. Often used to measure electrical activity in the body.

ELECTROENCEPHALOGRAPHY (EEG) - The recording of brain waves. Such tracings often give an accurate picture of brain disease or injury.

ELECTROMYOGRAPH (EMG) - An instrument which records the electrical impulses that pass through a muscle as it contracts and relaxes. Can tell what kinds of nerves are involved in pain transmission, yielding a more accurate and complete Dx.

ELECTRONEGATIVITY - the affinity of an atom for electrons. The most electronegative element is F (fluorine), at 4.0; it drops off as one goes down the column or left (along the row) along the Periodic Table. The difference in electronegativity between two bonded atoms determines the polarity of the bond.

EMPATHY - Understanding, being aware of, being sensitive to, and vicariously experiencing the feelings, thoughts, and experience of another without having the feelings or thoughts.

EMPHYSEMA - a form of chronic obstructive pulmonary disease (COPD), which is a chronic lung disease. The emphysema form of the disease causes slow destruction of the lungs and often leads to death. There is no cure for it, but the most common known cause is the smoking of tobacco. Secondhand smoke and environmental toxins can also contribute to the disease. Chronic obstructive pulmonary disease takes some time to develop, so symptoms may not appear until it is well progressed.

ENDOGENOUS - made or released from within the body. Endorphins are endogenous opioids, since the body manufactures them.

ENDORPHIN - One of the three major groups of endogenous opioid peptides. They are large peptides derived from the pro-opiomelanocortin precursor. The known members of this group are alpha-, beta-, and gamma- endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; opioid peptides is used for the broader group.

ENDOSCOPE - An instrument used to look into body cavities and openings, such as a gastroscope used to examine the stomach.

ENDOTHERMIC - used to describe a process or reaction that absorbs heat as it progresses. Compare with exothermic.

ENKEPHALIN - One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.

ENTHALPY - the total heat in a system, usually used in expressing a change in heat (the thermodynamics) during a transformation. A change in enthalpy is abbreviated ΔH.

ENTROPY - generally thought of as the degree of disorder in a system. Thus, moving from a solid to a liquid to a gas represents an increase in entropy. A change in entropy is abbreviated ΔS.

ENZYME - A protein molecule that catalyzes chemical reactions of other substances. Enzymes are classified according to the recommendations of the Nomenclature Committee of the International Union of Biochemistry. Each enzyme is assigned a recommended name and an Enzyme Commission (EC) number. They are divided into six main groups; oxidoreductases, transfcrases, hydrolases, lyases, isomerases, and ligases.

EPIDIDYMITIS - occurs when the epididymis becomes swollen. The epididymis is a tube behind the testicle that supplies sperm to the vas deferens before ejaculation occurs. There is one of these tubes attached to each testicle in males. This illness can happen to any male. However, males between 14 and 35 years of age are more likely to experience epididymis swelling.

EPIDURAL - the CSF-filled space adjacent to the spinal cord, into which local anesthetics are injected during an epidural spinal block (see diagram to the right).

EPINEPHRINE - aka adrenalin, this is a powerful stimulant of the sympathetic nervous system, and thus is a sympathomimetic drug. It is the drug of choice for heart attack, anaphylactic shock, and other medical emergencies involving stoppage of the heart contractions.

ERYTHEMA - A patch of redness of the skin.

ETHICS - A system of moral principles and rules that are used as standards for professional conduct. Many hospitals and other health care facilities have ethics committees that can help doctors, other healthcare providers, patients and family members in making difficult decisions regarding medical care.

ETIOLOGY - The cause, or development, of a specific disorder or disease.

EUTHANASIA - Physician-administered means of death.

EXACERBATION - Flare-up or relapse of a condition or disease; generally, a worsening of symptoms and signs.

EXCLUSION CRITERIA - The characteristics that render potential subjects ineligible to participate in a particular study or that render studies ineligible for inclusion in a systematic review.

EXOTHERMIC - used to describe a process or reaction that gives off heat as it progresses. Compare with endothermic.

EXTENSION - the opposite of flexion, describing a straightening movement that increases the angle between body parts. When a joint can move forward and backward, such as the neck and trunk, extension refers to movement in the posterior direction.

EXTRACTION - The process or act of pulling or drawing out.

EXTREMITY - A limb; an arm or leg (membrum); sometimes applied specifically to a hand or foot.


FAILED BACK SURGERY SYNDROME (FBSS) - Pain that persists or recurs after surgery for lumbosacral spinal disease (disease of the lower back).

FALSE NEGATIVE - Those who have the target disorder but the test incorrectly identifies them as not having it.

FALSE POSITIVE - Those who do not have the target disorder, but the test incorrectly identifies them as having it.

FASCIA - Connective tissue located in various places throughout the body, such as beneath the skin, in between muscles, around blood vessels or nerves, etc. When the foot plantar fascia become inflamed, the result is plantar fasciitis, one of the most common overuse injuries that runners are prone to, especially if the calf muscles aren't regularly stretched.

FATIGUE - The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli.

FEBRILE - Feverish; relating to an elevation in body temperature above 98.6° F (37° C).

FIBROMYALGIA (FM) - Sometimes called fibrositis, this is a common condition that is associated with widespread aching, stiffness and fatigue, and originates in muscles and soft tissues. One drug, pregabalin (Lyrica®), is FDA-approved for the Tx of FM.

FIBROSIS - Thickening and scarring of connective tissue which replaces the normal components of a structure.

FIBROUS DYSPLASIA - characterized as a skeletal disorder in which scar-like tissue develops where normal bone once was. Healthy bone is then replaced by this fibrous tissue. This process of bone replacement can lead to chronic pain, fracture and misshapen bones, particularly when it occurs within longer bones including extremities such as arms and legs.

FIBULA - the smaller of the two main bones of the shin, adjacent to the tibia.

FLEXION - describes a bending movement that decreases the angle between two parts. For example, bending the elbow, or clenching a hand into a fist, are examples of flexion. When sitting down, the knees are flexed. The opposite of flexion is extension.

FLUORINE - one of the halogens, the most electronegative element known is a pale yellow gas as a molecule (F2). Incorporated into many drug molecules, it is not much larger than a proton and confers predictable properties on molecules containing it, particularly in the "depth" or "strength" of their pharmacological action.

FLUOROSCOPY - Real time x-raying a part of the body and displaying the rays on a fluorescent screen. This is carried out in order to view various organs in motion, to accurately place a needle for a neural block, and many other applications.

FRAILTY - A diminished capacity to withstand stress that places individuals at risk for adverse health outcomes. Frailty is progressive, is associated with chronic disease, worsens with advancing age, and is often marked by a transition from independence in activities of daily living to dependence on caregivers.

FREE ENERGY - the total energy of a chemical system (ΔG); a function of a system's enthalpy and entropy, as well as the system's temperature, as follows: ΔG = ΔH - TΔS. The free energy of a reaction predicts whether the reaction is exothermic or endothermic and thus whether the reaction is thermodynamically favorable or not. This does not necessarily correlate with a reaction's spontaneity.

FROZEN SHOULDER - Frozen shoulder, or adhesive capsulitis, is a condition that causes restriction of motion in the shoulder joint.

fMRIFUNCTIONAL DISEASE - One associated with a disruption of function rather than a change in structure, such as migraine headaches, mucous colitis, etc.

FUNCTIONAL MAGNETIC RESONANCE IMAGING (fMRI) - aka "dynamic MRI", fMRI enables the real-time visualization of soft tissue in the body in great detail. Has enabled the mapping of very small areas of the brain that coincide with certain thoughts, movements, emotions, and other intriguing metrics of mental activity. Destined to grow in diagnostic utility.


GABAPENTIN - aka Neurontin, an anti-seizure drug with strong analgesic effects against neuropathic pain. A drug that is not metabolized by the body at all, so that, even at high doses (several grams/day), there is no organ toxicity. Tends to cause many neurological side-effects, including forgetfulness, vertigo, inability to concentrate, etc. Compare to pregabalin (Lyrica®).

GALL BLADDER - a pear-shaped organ located below the liver that stores the bile secreted by the liver. During and after a fatty meal, the gallbladder contracts, delivering the bile through the bile ducts into the intestines to help with digestion.

GASTRITIS - a medical condition that occurs when the lining of the stomach becomes swollen or inflamed. Gastritis can also cause the lining of the stomach to erode. Although many people can suffer from acute gastritis, or gastritis that only lasts for a short period of time, others suffer from long-term, or chronic, gastritis. Gastritis is often caused by long term use of over the counter pain relievers such as aspirin, ibuprofen or naproxen. Long-term, and/or excessive use, or abuse, of alcohol can also lead to gastritis.

GASTROESOPHAGEAL REFLUX DISEASE (GERD) - is a digestive disorder that causes acid indigestion or heartburn by the return of acidic stomach juices, or sometimes food, back up into the esophagus.

GASTROPARESIS - also called delayed gastric emptying, is a medical condition consisting of a paresis (partial paralysis) of the stomach, resulting in food remaining in the stomach for an abnormally long time.

GANGLION CYST - A cyst of the sheath of a tendon, frequently appearing about the wrist.

GENERIC (DRUG) - a drug available after the patent protection for the name-brand drug has expired, allowing other manufacturers to make and sell the same drug, as long as it is proven to the FDA that the generic is bioequivalent (functions identically in the body) to the name-brand drug. Attractive to consumers since generics are typically far less expensive than the name-brand medications. An example is Valium®, now available as diazepam (the drug name) from dozens of manufacturers around the world.

GENETIC HETEROGENEITY - A situation in which a particular phenotype may result from more than one genetic variant.

GENITAL HERPES - An inflammatory skin disease in the genital area caused by herpes simplex virus or varicella-zoster virus; an eruption of groups of deep-seated vesicles on erythematous bases. Symptoms include small red bumps, blisters (vesicles) or open sores (ulcers) in the genital, anal or nearby area; and pain or itching around the genital area, buttocks or inner thighs.

GENOME - The entire collection of genetic information (or genes) that an organism possesses.

GENOTYPE - the genetic makeup of an organism (or individual), usually in considering a specific trait. One's genotype, along with "epigenetic" (inherited, but not via DNA) and environmental variables, result in the overall appearance and function, known as one's phenotype.

G.I. - gastrointestinal, meaning the parts of the body involved in digestion; these are primarily the stomach, duodenum, small intensine, and large intestine. This organ system is referred to as the G.I. tract.

GLAND - An organ that makes and secretes substances used by the body.

GLAUCOMA - A disease of the eye characterized by increased intraocular (within the eye) pressure, excavation, and atrophy of the optic nerve; produces defects in the field of vision and eventual blindness. Symptoms include gradual loss of peripheral vision, tunnel vision in the advanced stages, severe eye pain, nausea and vomiting, sudden onset of visual disturbance, blurred vision, halos around lights and reddening of the eye.

GLUCOSE TOLERANCE TEST - A blood test to determine the presence of diabetes or a tendency towards its development. It is also used to determine the presence of hypoglycemia.

GOUT - A type of arthritis or inflammation about a joint caused by excess uric acid in the blood. Attacks occur suddenly and are accompanied by great pain. The big toe is a frequent site.

GRAVES DISEASE - an autoimmune disorder that results in hypothyroidism, or overproduction of thyroid hormones in the body. Among all the possible reasons for hyperactivity within the thyroid, Graves Disease is the most common cause.

GUARDING, INVOLUNTARY - A reflexive spasm of the abdominal musculature in the setting of peritoneal irritation, such as with appendicitis, which cannot be overcome by distraction (also referred to as rigidity).

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HALF-LIFE - Half-life (t½) is an important pharmacokinetic measurement. The metabolic half-life of a drug in vivo is the time taken for its concentration in plasma to decline to half its original level. Half-life refers to the duration of action of a drug and depends upon how quickly the drug is eliminated from the plasma. The clearance and distribution of a drug from the plasma are therefore important parameters for the determination of its half-life.

HALLUCINOGEN - a substance that causes hallucinations - profound distortions or disturbances of one's perceptions and mental processes, including the perception that unreal things are, in fact, real. Often accompanied by intense emotional swings and even panic attacks. Among well-known hallucinogens are lysergic acid diethylamide (LSD), mescaline (peyote), dimethyltryptamine (DMT), and psilocybin (mushrooms).

HANSCH COEFFICIENT - a quantitative measurement of the lipophilicity of a drug or other compound, denoted as "rho" (ρ).

HBO - Hyperbaric oxygen. Please see Hyperbaric Oxygen Chamber.

HEADACHE - Pain in the head; also called cephalalgia.

HEMATEMESIS - Vomiting of blood.

HEMATOMA - Tumor-like mass produced by an accumulation of coagulated blood in a cavity. Hematomas are the result of a severe blunt injury with extensive soft tissue damage, tearing of large blood vessels, and pooling of large amounts of blood below the skin.

HEMIPLEGIA - Paralysis of one side of the body.

HEMOPHILIA A - The largely inherited bleeding disorder is caused by a lack of blood clotting factor VIII. The disease is caused by an inherited X-linked recessive trait, with the defective gene being located on the X chromosome. The vast majority of people who suffer from Hemophilia A are males. The reason for this is that females have two X chromosomes while males only have one.

HEREDITARY - Passed down from generation to generation.

HIPAA - Enacted by the US Congress, HIPAA (Health Insurance Portability and Accountability Act) protects health insurance coverage for workers and their families when they change or lose their jobs and requires the establishment of national standards for electronic health care transactions and national identifiers for providers, health insurance plans, and employers to protect patients' privacy.

HISTAMINE - A depressor amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.

HOLISTIC MEDICINE - That type which considers the individual as a whole, and places responsibility for maintenance of health upon the individual himself.

HOMEOPATHY - A branch of medicine, characterized by the treatment of illness with extremely small doses of drugs that produce, in a healthy person, symptoms like those of the illness being treated. Has never survived a controlled clinical trial.

HORMONE - Chemical substance having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various endocrine glands and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.

HORNER'S SYNDROME - Drooping of the eyelid, contraction of the pupil, and flushing of the face, seen in persons who have had sympathetic nerve destruction in the neck. Symptoms are often seen temporarily after a stellate ganglion block.

HOSPICE - A special way of caring for people with terminal illnesses and their families by meeting the patient’s physical, emotional, social, and spiritual needs, as well as the needs of the family. The goals of hospice are to keep the patient as comfortable as possible by relieving pain and other symptoms, to prepare for a death that follows the wishes and needs of the patient, and to reassure both the patient and family members by helping them to understand and manage what is happening.

HYDROCODONE - a strong semisynthetic opioid, active principle in Vicodin®, Lortab®, and others. Recently up-scheduled by the FDA (due to ongoing pressure from the DEA) from C-III to C-II, in an attempt to slow the amount of diversion to illicit uses. We'll see how that works out.

HYDROMYELIA - also known as Syringomyelia, a condition characterized by the abnormal widening of the central canal of the spinal cord. This widening works to create a cavity in which cerebrospinal fluid can build up, creating abnormal increased pressure on the spinal cord and damaging nerve cells and their connections.

HYDROMORPHONE - a very high-potency semisynthetic opioid, synthesized from thebaine, a constituent of poppy straw - Dilaudid®.

HYDROPHILIC - literally, "water-loving". A compound or structure that is soluble in water, or more stable when in water.

HYDROPHOBIC - literally, "water-fearing". A compound or structure that is insoluble in water or unstable in it.

HYDROSIS - Excessive perspiration.

HYPERALGESIA - Extreme sensitivity to pain and lowered threshold to painful stimuli. Hyperalgesia of the skin may be manifested by great pain even on light pinching or touch. Many cases of hyperalgesia have features of allodynia. A consequence of central sensitization.

HYPERASTHESIA - Over-sensitivity to touch and light pressure; very similar to hyperalgesia.

HYPERBARIC OXYGEN (HBO) CHAMBER - A specially devised room/chamber in which the oxygen content is greater than under ordinary atmospheric conditions. Has shown great promise in many diseases where high blood oxygen is desirable (like CRPS, chronic wounds, etc.).

HYPERESTHESIA - Excess sensitivity, such as to touch or pinprick.

HYPERGLYCEMIA - Excessive sugar in the blood.

HYPERHYDROSIS - Excessive sweating.

HYPERPATHIA - A painful syndrome, characterized by increased reaction to a stimulus, especially if repetitive. Hyperpathia may occur with hyperesthesia, hyperalgesia, or dysesthesia. Faulty identification and localization of the stimulus, delay, radiating sensation, and after-sensation may occur. The pain is often explosive in character.

HYPERPIESIS - High blood pressure; hypertension.

HYPERPNEA - Rapid and exceptionally deep breathing.

HYPERPYREXIA - High fever.

HYPERTENSION - High blood pressure. Most of the time, there are no symptoms. Symptoms that may occur include: chest pain, confusion, ear noise or buzzing, irregular heartbeat, nosebleed, tiredness or vision changes.

HYPERVENTILATION - rapid or very deep breathing that results in lowered carbon dioxide levels in the body. As a person breathes, he or she pushes out carbon dioxide. Deeper breaths mean more carbon dioxide coming out. Rapid breathing does the same thing, but by pushing it out faster, not by pushing out more at once.

HYPESTHESIA - Decreased sensitivity, as lessened appreciation of the sense of pain or touch.

HYPNOTHERAPY - The treatment of disease by inducing a trance-like sleep. Can be used to relieve chronic pain.

HYPNOTIC - 1. capable of inducing sleep. 2. a drug used to induce sleep.

HYPOALGESIA - Diminished sensitivity to noxious, especially painful, stimulation.

HYPOESTHESIA - Diminished sensitivity to stimulation, excluding special senses.

HYPOGLYCEMIA - Too little sugar in the blood. This condition can produce a variety of symptoms and effects but the principal problems of this condition arise from an inadequate supply of glucose to the brain. This can result in an impairment of regular functions. Effects can range from mild dysphoria or lead to a more serious concern such as seizures, unconsciousness and sometimes permanent brain damage or death.

HYPOPNEA - Shallow breaths or low respiratory rate.

HYPOREFLEXIA - Diminished reflexes.

HYPOTENSION - Low blood pressure.

HYPOTHENAR - The fleshy part of the palm of the hand in the region of the ring and little fingers.

HYPOTHYROIDISM - A condition where the thyroid gland makes too little or no thyroid hormone. Symptoms and signs may include: coarse and thinning hair, dry skin, brittle nails, a yellowish tint to the skin, slow body movements, cold skin, inability to tolerate cold, feeling tired or weak, memory problems, depression, difficulty concentrating, or constipation. Can be congenital or acquired.

HYPOTONIA - Lessened muscle tone.

HYPOXEMIA - Deficient oxygenation of the blood.


IATROGENIC - induced inadvertently by a physician or surgeon or by medical treatment or diagnostic procedures. For instance, iatrogenic drug addiction.

IDIOPATHIC - Of unknown cause; of the nature of an idiopathy; self- originated.

IMMUNE REACTION - The body’s defense reaction that recognizes an invading substance (an antigen, such as a virus, fungus, bacteria or transplanted organ) and produces antibodies against that antigen.

IMMUNE SYSTEM - The body mechanism that protects against harmful invaders, including the production of antibodies. Centered in a number of organ systems, as shown in the graphic to the right.

IMPALPABLE - Not able to be felt with the hands, such as some tumors.

IMPOTENCE - a psychological condition where a male erection or penetration fails due to thoughts or feelings (psychological reason) rather than physical impossibility. This condition could be considered somewhat less frequent but often can be treated accordingly. In psychological impotence, there is a notably strong response to placebo treatment.

IN VITRO - Latin for "in glass", usually refers to biological tests done in laboratory glassware, as opposed to tests done on live animals. Tests done in living systems are called in vivo - Latin for "in the living".

IN VIVO - Latin for "in the living", usually refers to biological or medicinal tests done with live animals. This is contrasted with tests done in laboratory glassware, which are termed in vitro ("in glass").

INDEPENDENTLY MAINTAINED PAIN - (IMP) Pain which stops reacting to methods of pain relief. As RSD progresses, more of the pain becomes independently maintained, which explains why localized pain reduction techniques (i.e., sympathetic blocks, creams etc.) no longer work. Also called Sympathetically Independent Pain (SIP).

INDURATION - Thickening, such as might be felt around the edges of an inflamed wound.

INDWELLING CATHETER - A catheter that is left in place for prolonged periods of time.

INFECTION - Invasion of the body tissues by bacteria or other micro-organisms that cause illness.

INFLAMMATION - The reaction of tissues to injury, manifested by pain, heat, swelling, and redness. Many specific processes occur during inflammation, which are outlined in the great graphic to the right.

INFLAMMATORY AUTOIMMUNE-MEDIATED ARTHRITIS - associated with any immune-mediated inflammatory disease. This can consist of any group of conditions or diseases that lack a definitive etiology, or causation of the disease. This condition is best characterized by common inflammatory pathways leading to inflammatory. This may or may not be a result from a dysregulation of the normal condition.

INFLAMMATORY BOWEL DISEASE (IBD) - a group of inflammatory-based conditions that directly affect the areas of the colon and small intestine. The major types of inflammatory bowel disease are Crohn's disease and ulcerative colitis. Inflammatory bowel diseases are considered autoimmune diseases, in which the body's own immune system attacks elements of the digestive system and causes great disruption.

INFLAMMATORY RESPONSE - Irritation of the involved extremity, which may include localized heat, swelling, redness, pain, and limited movement and occur when tissues are injured by viruses, bacteria, trauma, chemicals, heat, cold or any other harmful stimulus.

INFORMED CONSENT - The process of making decisions about medical care that are based on open, honest communication between the health care provider and the patient and/or the patient's family members.

INNERVATION - 1. the distribution or supply of nerves to a part. 2. the supply of nervous energy or of nerve stimulus sent to a part.

INSOMNIA - also referred to as sleeplessness, a sleep disorder in which an individual has the inability to fall asleep or stay asleep as long as is desired. While the term insomnia is used to describe a disorder that is demonstrated by polysomnographic evidence of disturbed sleep, it is often best defined as a positive response to either one of two questions: Either a patient has difficulty sleeping or they have difficulty falling asleep or staying asleep. Sleep problems are often associated with psychiatric problems such as depression.

INTENSIVE CARE UNIT - Medical facility with the services and devices to meet the needs of the critically ill.

INTERMITTENT - Occurring at separated intervals; having periods of cessation of activity.

INTERMITTENT CLAUDICATION - Reproducible leg pain of vascular etiology that occurs with exercise, does not occur at rest, and is relieved within 10 minutes of rest.

INTERSTITIAL CYSTITIS - Interstitial cystitis (also known simply as painful bladder syndrome) is a debilitating condition in which patients tend to experience bladder pressure, bladder pain and sometimes pelvic pain.

INTESTINES - The long, tube-shaped organ in the abdomen (also called the bowels), that runs from the stomach to the anus and completes the process of digestion.

INTRACRANIAL HEMORRHAGE - Bleeding that occurs within the skull. Bleeding within the brain is a cerebral hemorrhage. Bleeding within the skull but outside the brain includes epidural hematoma, subdural hematoma, and subarachnoid hemorrhage.

INTRACTABLE - Incurable; impossible to control.

INTRAMUSCULAR - within a muscle; a common injection technique, especially for suspensions or oily solutions. The most common sites are the deltoid and gluteus maximus/medius muscles.

INTRATHECAL DRUG DELIVERY (IDD) - With IDD, pain-relieving medicine is delivered by an intrathecal pump though a small, soft tube (catheter) directly into the intrathecal space, the fluid-filled area around the spinal cord.

INTRATHECAL PUMP - A method of pain relief which uses a small pump that is surgically placed under the skin of the abdomen to deliver morphine or other medications directly into the intrathecal space (where fluid flows around the spinal cord). The medication is delivered through a small tube called a catheter that is also surgically placed.

INTRAVENOUS - into a vein, a common route for drug introduction, especially when rapid onset of action is desired. Also commonly employed to avoid the destructive influence of the digestive system on a drug.

IODINE - one of the halogen elements, used in synthetic chemistry and is essential in the human diet. A diatomic molecule (I2), this dark blue-black solid gives off toxic iodine vapors at room temperature and is an extremely dangerous and toxic chemical.

IONIC BOND - the electromagnetic attraction of a cation for its anion partner in an ionic compound, such as salt, NaCl. To form this bond, the sodium (Na) gives up an extra electron (making it positive) to chlorine (Cl) (making it negative). Thus, salt is most correctly represented as Na+Cl-. Compare to covalent bond.

IRRITABLE BOWEL SYNDROME (IBS) - An illness in which there are intermittent periods of abdominal cramps and diarrhea. Has a considerable emotional component.

ISCHEMIA - Lack of blood supply to an organ or part due to a spasm or shutting down of the artery which supplies it.

ISOTOPE - variant of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom. Isotopes occupy the same place on the periodic table, but have different atomic weights.


JOINT - the point of articulation of two (or more) bones, giving flexibility.


KAPPA (κ) OPIOID RECEPTOR - One of the three opioid receptor subtypes; its actions include analgesia, depression, and dysphoria.

KETAMINE - a powerful drug that has shown much promise in the Tx of CRPS. It is a member of the drug class called "NMDA receptor antagonists". Originally popularized as a drug of abuse, with street names such as "Special K", ketamine causes a dissociative state which, in predisposed individuals, precipitate a psychotic episode.

KIDNEY DISEASE - A condition in which the kidneys gradually fail to function properly, this causes fluids and waste products to build up in the body. In some cases, kidney failure may cause peripheral nerve damage.


LANCINATING PAIN - A shooting, knife-like, sudden, severe pain characteristic of neuropathic pain, especially in its early stages.

LAPAROTOMY - A surgical procedure involving an incision through the abdominal wall in order to access the abdominal cavity.

LATERAL - Toward the outside of the body. Its opposite is medial.

LESION - any abnormality in the tissue of an organism (in layman's terms, "damage"), usually caused by disease or trauma. Lesion is derived from the Latin word laesio meaning injury. If this sounds incredibly broad, that's because it is.

LETHAL - Deadly, fatal.

LEUCOCYTE - White blood cell.

LIDOCAINE - A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of procaine but its duration of action is shorter than that of bupivacaine or prilocaine.

LIGAMENT - A band of fibrous tissue that connects bones or cartilages, serving to support and strengthen joints.

LIGAND - in medicinal chemistry, a molecule or other entity that interacts with and forms a complex with a receptor. Can be a drug as well as an entity with a different purpose.

LIGHTNING PAINS - Severe, sharp pains, usually caused by nerve irritation.

LIPOMATOSIS - a heredity condition that causes groups of fat cells to grow in the subcutaneous tissue of the body, resulting in many fatty lumps just below the skin’s surface, referred to as a “limpoma“. Although these lipomas may grow deeper in the body or in the organs, they are most commonly found on the torso, upper arms, shoulders or neck but can also appear on the head, buttocks or other body areas.

LIPOPHILIC - literally, "fat-loving". A compound or structure that is soluble in fats/oils, or more stable when in fatty tissue. Usually very nonpolar. Lipophilic drugs tend to accumulate in lipid stores in the body, extending their duration of action. Such drugs typically have a rapid onset of action since their nonpolar properties enable crossing the blood-brain barrier quite easy.

LIPOPHOBIC - literally, "fat-fearing". A compound or structure that is insoluble in fats/oils or unstable in them. Not commonly used.

LIVING WILL - A legal document which outlines the kinds of medical care a patient wants and doesn't want. The living will is used only if the patient becomes unable to make decisions for him/herself.

LOCAL ANESTHETIC - A medicine that causes a complete loss of feeling to a specific part of your body without causing you to lose consciousness. It works by blocking the nerves from the affected part of your body so that pain signals cannot reach your brain.

LUPUS - A form of cutaneous tuberculosis. It is seen predominantly in women and typically involves the nasal, buccal, and conjunctival mucosa.

LUPUS ERYTHEMATOSUS - An acute or chronic disease of the skin, evident mostly on the face and hands. The face rash is red, scaly, blotchy and often extends across the nose to the cheeks in a "butterfly" formation.

LYME DISEASE - A condition thought to be transmitted through the bite of a tick, characterized by a ring-shaped rash surrounding the bite area, fever, and attacks of pain and stiffness that resembles arthritis. Appears to be capable of long chronicity.

LYMPHATIC OBSTRUCTION - A blockage of the lymph vessels that drain fluid from body tissues and facilitate immune system cell movement through the body. Lymphatic obstruction can be caused by such things as tumors, surgery, injury and infection. Obstruction can be primary (as in the case of inherited conditions such as lymphatic hypoplasia) or secondary (as in the case of infection).

LYMPHOCYTE - one of three types of white blood cells which are an important part of vertebrates' immune systems: natural killer cells, T-cells, and B-cells.

LYMPHOMA - the name given to a broad group of blood cancers that develop within the lymphatic system. Lymphoma is sub-divided into two general categories -- non-Hodgkin’s Lymphoma and Hodgkin’s Lymphoma.

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MAGNETIC RESONANCE IMAGINING (MRI) - A technique for viewing internal organs and bones; and for creating many of the images formerly revealed only by X-rays. MRI's use no radioactive rays. The technique was developed by chemists, who called it nuclear magnetic resonance (NMR), but once applied to living systems, the decision was made to keep out the word "nuclear". Evidently the public was wary of being scanned by a machine with the word "nuclear" in its title.

MAJOR DEPRESSIVE DISORDER - The official Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) diagnostic term for depression, a mood disorder marked by sadness, inactivity, difficulty with thinking and concentration, a significant decrease (or increase) in appetite and time spent sleeping, feelings of dejection and hopelessness, and sometimes suicidal thoughts or an attempt to commit suicide.

MALAISE - A feeling of being ill or unwell, particularly as evidenced by a lack of energy.

MALIGNANT - cancerous, containing cancer cells.

MALIGNANT MELANOMA - a neoplasm of melanocytes or a neoplasm of the cells that develop from melanocytes. Although this condition was once considered an uncommon occurrence, the annual incidence of this condition occurring and being diagnosed, has increased drastically over the past few decades. Usually, the definitive treatment for early-state melanoma is surgery.

MANIA - a state of abnormally elevated or irritable mood, arousal or other energy levels. In a certain sense of the term mania, it is the opposite of depression. Mania is a criterion for certain psychiatric diagnoses.

McGILL PAIN SCALE - the most popular of various scales to help people communicate the degree of pain they're experiencing. The scale goes from 0 (zero pain) to 10 (worst pain conceivable). The average person is estimated to experience a maximum pain of 7/10 as the most painful thing they will experience during their lifetimes. Composite McGill scales run from 0 to 50, such as the one featured in the graphic to the right.

MEDIAL - Toward the inside of the body. Its opposite is lateral.

MEDITATION - A self-directed practice for relaxing the body and calming the mind. Meditation is one technique of alternative medicine used to relieve chronic pain.

MELAGIA - Pain in the arms or legs.

MEMBRANE - A thin layer of tissue which covers a surface, lines a cavity or divides a space or organ.

MENISCUS - Crescent shaped cartilage, usually pertaining to the knee joint; also known as "cartilage." There are two menisci in the knee, medial and lateral. These work to absorb weight within the knee and provide stability.

META-ANALYSIS - A statistical technique for quantitatively combining the results of multiple studies that measure the same outcome into a single pooled or summary estimate.

METABOLISM - As applied to drugs, this is the process by which the body converts a drug compound into one which is more water-soluble,metabolism since only water-soluble compounds can be eliminated via the kidneys in the urine. A compound which is formed via metabolism is called a "metabolite". This is done by either changing the chemical makeup of the drug or bonding the drug molecule to a very water-soluble compound available in the body (such as glucuronic acid).

METABOLITE - the product of metabolism of a drug molecule. The body can do a series of chemical steps on a drug, in order to increase its polarity and thus its water-solubility, which enables its excretion via the urine. Occasionally, metabolites possess similar activity to the parent drug, which must be considered when deciding metacarpals what dose is appropriate.

METACARPALS - Five long bones of the hand, running from the wrist to the fingers.

metatarsalsMETATARSALS - Five long bones of the foot, running from the ankle to the toes.

METENCEPHALON - The metencephalon is composed of the pons and the cerebellum.

METHADONE - A synthetic opioid medication used in stable doses for pain relief in treatment of chronic pain, in maintenance doses for treatment of opioid addiction (by addiction specialists), and in gradually escalating doses for pain relief in treatment of terminal illness.

METHAMPHETAMINE - a heavily-abused amphetamine derivative, addiction to which establishes quickly.

MIDAZOLAM - A short- acting benzodiazepine, water- soluble at pH less than 4 and lipid- soluble at physiological pH. It is a hypnotic-midazolamsedative drug with anxiolytic and amnesiac (retrograde) properties. It is used for sedation in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. Because of its short duration and cardiorespiratory stability, it is particularly useful in poor-risk, elderly, and cardiac patients.

MIGRAINE - Severe headache often associated with spots before the eyes, nausea and vomiting. The attacks tend to come on suddenly and are recurrent. Can be treated during an attack or prophylactically with various drugs, often in the triptan or ergot family of molecules. Has a genetic correlation, and often begins later in life, although children can also suffer migraines.

MINIMALLY INVASIVE SURGERY - Operations performed through an endoscope or laparoscope, utilizing the smallest incisions, some no more than 1/2" long.

MOBILIZATION - The process of making a fixed part or stored substance mobile, as by separating a part from surrounding structures to make it accessible for an operative procedure or by causing release into the circulation for body use of a substance stored in the body.

MORPHINE - the "gold standard" of analgesic drugs, against which all others are compared. Morphine (usually sold as the sulfate salt) is a "pure μ-agonist", meaning that, theoretically, there is no ceiling to its action; i.e., there is no maximum dose. It also has minimal effects at the other two primary opioid receptors. In practice, side-effects, especially respiratory depression, limit the maximum dose of all opioids. All side effects are subject to tolerance development, with the unfortunate exception of constipation.

MORTALITY - Measure of rate of death.

MORTON'S NEUROMA - Involves the nerves and is usually the result of a trauma to the foot, causing inflammation and sharp pain, usually between the third and fourth toes.

MOTION SICKNESS - a blanket term for symptoms that arise due to a number of different motions or simulated motions. Common types of motion sickness include airsickness, carsickness and seasickness. In some cases, the symptoms arise when a person feels motion, but cannot see it, such as with airsickness. In other cases, the motion is visual but not physical.

MOTTLED - Marked with blotches, streaks, and spots of different colors or shades.

MUCOSITIS - Inflammation of the mucosal membranes lining the gastrointestinal tract. It often affects the mouth and pharynx of patients with head and neck cancer who undergo radiation therapy.

MULTIPLE SCLEROSIS - A disorder of the body’s immune system that affects the nerves and develops slowly over time. MS affects a person's ability to move, to feel and control his or her body functions, and can be associated with chronic pain.

MU (μ) OPIOID RECEPTOR - the primary receptor subtype for opioids, the action of which results in analgesia, euphoria, physical dependence, respiratory depression, and reduced GI motility (i.e., constipation).

MUSCLE RELAXANTS - group of drugs that subdue or reduce the intensity of muscle spasms and thus tend to relieve the pain accompanying the spasms. Represented by drugs like Flexiril®, baclofen, Valium®, methocarbamol (Soma®), and others.

MUTATION - A rare variant in a gene, occurring in <1% of a population.

MYALGIA - Pain in muscles, as in lumbago, rheumatism, etc.

MYASTHENIA GRAVIS - an autoimmune and neuromuscular disease that is responsible for fluctuating muscle weakness and overall fatigue. Muscle weakness is caused by the body's many circulating antibodies that block acetylcholine receptors at the postsynaptic neuromuscular junction, inhibiting the excitatory effects of the neurotransmitter acetylcholine on nicotinic receptors at neuromuscular junctions.mylogram

MYELOGRAM - A diagnostic procedure where a radiopaque contrast dye is injected into the spinal canal. X-rays are then performed which reveal the anatomy of the spinal canal. Can be used to diagnosis disk disease, spinal stenosis and tumors of the spinal canal. MRI and CT scanning have largely displaced the use of this more invasive test.

MYELOID LEUKEMIA - a cancer of the myeloid line of blood cells and is best characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow of an individual. This process directly interferes with the production of normal blood cells in the body.

MYOCLONUS - Abnormal muscle twitchings.

MYOFASCIAL PAIN SYNDROME - Muscular pain in numerous body regions that can be reproduced by pressure on trigger points - localized hardenings in skeletal muscle tissue. Pain is referred to a location distant from the trigger points.

MYOFASCITIS - Inflammation of muscle and the fibrous coverings of muscle and surrounding ligaments. Seen as one of the common causes of chronic lower back pain.

MYOFIBROSIS - Replacement of muscle tissue by fibrous tissue, often the result of long-standing inflammation of a muscle.

MYOMALACIA - Degeneration of muscle.

MYOSITIS - Swelling and tenderness of muscle tissue. Myositis can be caused by injuries, diseases or certain drugs.

MYOTONIA - Spasm of muscle.


NARCOTIC - 1. pertaining to or producing narcosis. 2. an agent that produces insensibility or stupor, applied especially to the opioids, i.e., to any natural or synthetic drug that has morphine-like actions.

NATURAL HISTORY - As distinct from prognosis, natural history refers to the possible consequences and outcomes of a disease or condition and the frequency with which they can be expected to occur when the disease condition is untreated.

NATUROPATH - A non-medical practitioner who tries to cure or treat illness by giving "natural" remedies derived from such things as foods, herbs, water, etc.

NAUSEA - An unpleasant sensation, vaguely referred to the epigastrium and abdomen, and often culminating in vomiting.

NERVE - A bundle of fibers that transmit electrical messages between the brain and areas of the body; these messages carry sensations to the brain or instructions to the muscles from the brain.

NERVE BLOCK - The injection of an anesthetic agent into or around a nerve in order to block impulses which travel through it, producing loss of sensation to the area supplied by the nerve.

NERVOUS SYSTEM - A highly specialized network composed of nerves that transmit information to and from the brain and spinal cord to and from every other part of the body. The nervous system has two main divisions, the central nervous system and the peripheral nervous system.

NEURAL - 1. pertaining to a nerve or to the nerves. 2. situated in the region of the spinal axis, as the neutral arch.

NEURALGIA - Pain along the route of a nerve. Paroxysmal pain which extends along the course of one or more nerves. Many varieties of neuralgia are distinguished according to the part affected or to the cause, as brachial, facial, occipital, supraorbital, etc., or anemic, diabetic, gouty, malarial, syphilitic, etc.

NEURITIS- An inflammatory or degenerative condition of a nerve.

NEUROFIBROMATOSIS - a medical condition that refers to a number of various inherited conditions which are clinically and genetically distinct in nature. Each of these inherited conditions carry a high risk of tumor formation, particularly in the region of the brain. As an autosomal dominant disorder, only one copy of the affected gene is needed for neurofibromatosis to develop.

NEUROLEPTIC - A term coined to refer to the effects on cognition and behavior of antipsychotic drugs, which produce a state of apathy, lack of initiative, and limited range of emotion and in psychotic patients cause a reduction in confusion and agitation and normalization of psychomotor activity.

NEUROLOGIST - A physician who specializes in diseases of the nervous system.

NEURON - The basic cellular unit of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system.

NEUROPATHIC PAIN - Any pain syndrome originating in peripheral nerves and nerve roots. The pain is due to neurovascular damage such as diabetic neuropathy or sympathetically maintained pain (SMP), and is most characteristic of chronic pain. Neuropathic pain can affect any nerve in the body. An estimated 2 million people in the United States have neuropathic pain, as distinguished from nociceptive pain.

NEUROPATHY - Any disease or dysfunction of nerve tissues, usually involving pain. A general term denoting functional disturbances and/or pathological changes in the peripheral nervous system. The etiology may be known (e.g., arsenical neuro., diabetic neuro., ischemic neuro., traumatic neuro.) or unknown (idiopathic neuro.). Encephalopathy and myelopathy are corresponding terms relating to involvement of the brain and spinal cord, respectively. The term is also used to designate noninflammatory lesions in the peripheral nervous system, in contrast to inflammatory lesions (neuritis).

NEUROTOXICITY - the action of being damaging to nerve cells or tissue; toxic effects exerted on neural cells.

NEUROTRANSMITTER - Any of a group of substances that are released on excitation from the axon terminal of a presynaptic neuron of the central or peripheral nervous system and travel across the synaptic cleft to either excite or inhibit the target cell. Among the many substances that have the properties of a neurotransmitter are acetylcholine, norepinephrine, epinephrine, dopamine, glycine, y-aminobutyrate, glutamic acid, substance P, enkephalins, endorphins, and serotonin.

NEUROVASCULAR - A term that pertains to both the neurologic and vascular structures.

NEUTROPHILS - The most abundant type of white blood cells. They migrate toward the site of inflammation and are the predominant cells in pus.

NICOTINE - Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.

NIGHTMARE - What sets a nightmare apart from a simple dream is the level of anxiety and/or fear the dream causes. While an ordinary dream may not necessarily have a happy theme to it, a nightmare causes the dreamer to fear that he or she is in imminent harm. Common nightmare themes include being chased, injured, lost or threatened; however, nightmares are highly personal and may have anything as a theme as long as it causes terror in the dreamer.

NITROGEN TRIIODIDE - an extraordinarily sensitive contact explosive, NI3, produced by slurrying iodine crystals in concentrated ammonium hydroxide. Once dry, it can be set off literally by a slight breeze.

NMDA - N-Methyl-D-Aspartate (NMDA) is an animo acid derivative that can function as an excitotoxin - a drug that kills cells by over- activation. However, at low concentrations it's not neurotoxic, and can serve useful functions. Medicinally, the most useful drugs are those that block the action of NMDA at its receptor, and are thus known as NMDA receptor antagonists.

NMDA RECEPTOR ANTAGONIST - this is a drug which blocks, or antagonizes, the action of the excitatory compound NMDA; it acts as a dissociative anesthetic. Many synthetic opioids have this activity, including methadone and tramadol. Others have been used recreationally: ketamine (Special K), phencyclidine (PCP), nitrous oxide (laughing gas), and dextromethorphan. Ketamine has emerged as a very useful treatment for CRPS; typically, a benzodiazepine like midazolam (Versed®) is typically used to minimize any hallucinations or anxiety during ketamine infusions.

NNT - Abbreviation used in epidemiology as part of clinical testing, stands for "number needed to treat"; it represents the minimum number of patients receiving the Tx in order to see a positive result. Thus, the smallest possible NNT is one. The bottom line is that the smaller the number for a given drug in a study, the better.

NOCEBO - In medicine, a nocebo (Latin for "I shall harm") is an inert substance that creates harmful effects in a patient. The nocebo effect is the adverse reaction experienced by a patient who receives a nocebo, after being told it might have adverse effects. This is essentially the opposite of a placebo.

NOCICEPTIVE PAIN - According to the International Association for the Study of Pain, stimulation of a nociceptor due to chemical, thermal or mechanical event that has the potential to damage body tissue, may cause nociceptive pain. Also called acute pain.

NOCICEPTOR - Cutaneous and subcutaneous receptor (usually free nerve endings) specialized for the detection of harmful (noxious, painful) stimuli.

NOREPINEPHRINE (NE) - a very important neurotransmitter in the sympathetic nervous system (SNS, the "fight or flight" part of the nervous system), along with dopamine and serotonin. Aka "noradrenaline", NE causes a host of physiological effects, including peripheral vasoconstriction, decreasing appetite and digestion, increasing b.p., and increasing alertness.

NORTRIPTYLINE - a TCA often used in neuropathic pain control - Pamelor®. Not as dirty as Elavil®, but still laden with side-effects.

NSAID - a NonSteroidal AntiInflammatory Drug. Most of these are OTC drugs whose primary purposes are the reduction of pain, fever, and inflammation. This category encompasses a huge number of drug classes, usually accompanied by unpleasant side-effects, including irritation and bleeding in the GI tract. Well-known NSAIDs include aspirin and ibuprofen (and other "-profens"). Acetaminophen (Tylenol®) is NOT an NSAID due to its lack of appreciative antiinflammatory activity.

NUMBER NEEDED TO TREAT - An epidemiological measure used in communicating the effectiveness of a health-care intervention, typically a treatment with medication. The NNT is the average number of patients who need to be treated to prevent one additional bad outcome (e.g., the number of patients that need to be treated for one to benefit compared with a control in a clinical trial). Generally, the lower the NNT, the better the drug. Here's a short, entertaining video that explains it clearly.

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OBESITY - a medical condition in which excess body fat has began to accumulate to the extent that it may have an adverse effect on a patient's health. Obesity can lead to a reduced life expectancy and an increased amount of health complications. Individuals who are considered obese have a body mass index that exceeds 30 kg/m squared.

OBSESSIVE COMPULSIVE DISORDER (OCD) - Characterized by repeated and unwanted thoughts, feelings, fears, images or sensations that cannot be controlled, OCD can be disabling to a sufferer. The thoughts, feelings, ideas, fears, images or sensations can center around almost anything or anyone and make up the “obsessive” half of the disorder. The obsession then leads to an uncontrollable and urgent need to act on the obsession which creates the compulsive half of the illness.

OCCUPATIONAL THERAPY - Education and retraining for an injured or handicapped person, in an area in which they worked or anticipate being able to work.

ORTHOPEDIST - A physician who specializes in diseases and conditions of the bones, joints, muscles, tendon, ligaments, and cartilage.

OPIATE - a morphine-type of drug that is extracted from the opium poppy (Papaver somniferum) or is synthesized starting with an opium-derived chemical (called semi-synthetic). These include morphine, codeine, oxycodone (Percocet®, Tylox®, Roxicodone®), hydrocodone (Vicodin®, Lortab®), hydromorphone (Dilaudid®), and many others.

OPIOID - any drug that acts as an agonist at the opioid receptors, the main ones being μ (mu), δ, and κ. Thus, all opiates are opioids, but not visa-versa. Examples of opioids which are not opiates, being totally synthetic, are Demerol® (meperidine), methadone, Ultram® (tramadol), and fentanyl (along with its many derivatives and analogs).

OPIOID, CONTROLLED RELEASE - CR (Sustained Release) preparations consist of an opioid embedded in a wax matrix, micro-granules or other milieu that slowly releases the opioid into the GI tract or subcutaneous tissues. CR preparations of morphine, codeine, oxycodone and hydromorphone induce analgesia for up to 12 hours (e.g., MS-Contin®, Codeine-Contin®, OxyContin®, Hydromorph-Contin®). These CR preparations can be easily converted to immediate-release by biting or crushing the tablet. The duration of action of Kadian® (slow-release morphine) is 24 hours and for the transdermal fentanyl patch (e.g., Duragesic®), 72 hours. Tramadol is also available in a CR preparation (e.g., Zytram®, Tridural™, and Ralivia™).

OPIOID, IMMEDIATE RELEASE - IR formulations release the full dose of the opioid into the GI tract as the tablet dissolves. IR tablets generally contain a much smaller opioid dose than CR preparations. Some of the IR formulations also contain acetaminophen and caffeine. Examples of IR formulations include Tylenol® No. 1, 2, 3 and 4 (acetaminophen plus codeine), Percocet® and Oxycocet® (acetaminophen and oxycodone), Dilaudid® (hydromorphone), Statex® (morphine), Supeudol® (oxycodone), Codeine (codeine), and Tramacet® (tramadol 37.5 mg and acetaminophen 325 mg).

OPIOID RECEPTORS - the family of receptors that interact with opioid drugs. The general types are μ (mu), δ (delta), and κ (kappa), each of which causes a different set of reactions upon interaction with an opioid. The pharmacologically most important is the μ receptor.

OPIUM - The air-dried exudate from the unripe seed capsule of the opium poppy, Papaver somniferum, or its variant, P. album. It contains a number of alkaloids, but only a few - morphine, codeine, and papaverine - have clinical significance. Opium has been used as an analgesic, antitussive, antidiarrheal, and antispasmodic. In the image to the right, the seed pod has been slit vertically to allow the crude opium to collect on the outside as it dries.

ORGAN - An internal structure of the body that performs a various function (e.g., liver, brain etc.).

ORTHOPEDICS - A surgical specialty which utilizes medical, surgical, and physical methods to treat and correct deformities, diseases, and injuries to the skeletal system, its articulations, and associated structures.

ORTHOSTATIC HYPOTENSION - the lightheadedness many people feel when standing up from a sitting position. Caused by a temporary drop in cranial b.p. upon sudden standing.

OSTEOARTHRITIS - A form of arthritis associated with bone and cartilage degeneration; seen mostly in aging people. Basically results from loss of the cushioning membrane called the bursa, with resulting rubbing of bone against bone. Compare with rheumatoid arthritis.

OSTEOCHONDRITIS - Inflammation of a bone and cartilage.

OSTEODYNIA - Pain in a bone.

OSTEOPATHIC PHYSICIAN - One who uses the ordinary medical diagnostic and treatment measures, plus manipulative procedures which emphasize diseases of the bones. The terminal degree for osteopaths is the D.O. (Doctor of Osteopathy).

OSTEOPENIA - a thinning of the bones; a reduction in bone mass. Often occurs pre-osteoporosis.

OSTEOPOROSIS - A loss in bony substances producing brittleness and softness of bones; often seen in aging people or those with disability (weakness). Skeletal weakness leads to fractures with minor or unapparent trauma, particularly in the thoracic and lumbar spine, wrist, and hip (called fragility fractures). The graphic shows the matrix of healthy bone compared with bone that's osteoporotic; it's clear why such bone is so brittle.

OTC - "Over The Counter", usually refers to drugs that are available without a prescription.

OXYCODONE - a powerful, C-II opiate that is the active principle in Percocet®, Tylox®, Roxicodone®, etc. The most powerful oral narcotic available. Also comes without acetaminophen (*very* good idea) in strengths from 5mg to 30mg in 5mg increments.


PACEMAKER - A medical device which uses electrical impulses to regulate the beating of the heart.

PAIN - An unpleasant feeling that may or may not be related to an injury, illness, or other bodily trauma. Pain is complex and differs from person to person.

PAIN, ACUTE - Occurs when the body detects damage to tissues or disease, aka nociceptive pain. Nerve endings become over-stimulated or damaged, sending pain messages to the brain along the nerves. The pain is usually described as sharp or aching and may be helped by common painkillers, such as paracetamol, ibuprofen or codeine.

PAIN, BREAKTHROUGH - Transient or episodic exacerbation of pain that occurs in patients with pain that is otherwise considered stable but persistent.

PAIN, CHRONIC - ongoing or recurrent pain, lasting beyond the usual course of acute illness or injury or more than 3 to 6 months, and which adversely affects the individual’s well-being, aka neuropathic pain. A simpler definition for chronic or persistent pain is pain that continues when it should not.

PAIN MEDICINE - the specialty of Pain Medicine is a discipline within the field of medicine that is concerned with the prevention of pain, and the evaluation, treatment, and rehabilitation of persons in pain. Some conditions may have pain and associated symptoms arising from a discrete cause, such as postoperative pain or pain associated with a malignancy, or may be conditions in which pain constitutes the primary problem, such as neuropathic pains or headaches.

PAIN THRESHOLD - The point at which one feels pain. A person with a low pain threshold feels pain sooner than one with a high threshold.

PAIN TOLERANCE LEVEL - The greatest level of pain that a subject is prepared to tolerate. Because the pain tolerance level is the subjective experience of the individual, the same considerations limit the clinical value of pain tolerance level as pain threshold.

PAINKILLER - A substance such as a medication or herb used to relieve pain. See analgesic.

PALLIATIVE - A medication given to relieve, not to cure; or a form of treatment directed toward relief rather than a cure applied when true cure is not possible. Most patients in hospice are receiving palliative care.

PALMAR SURFACE - The palm or grasping side of the hand.

PALPATION - Application of fingers with light pressure to the surface of the body to determine consistence of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs.

PANCREAS - An organ that is responsible for secreting substances that aid digestion and the control of blood sugar.

PANIC DISORDER - Characterized by frequent attacks of intense, unfounded fear and anxiety, panic disorder can cause the sufferer to experience rapid heartbeat, dizziness, nausea and the inability to breathe normally. A severe attack may even leave the sufferer feeling as though he or she is going to die or is going crazy. Panic disorder can seriously interfere with both the quality and enjoyment of life for most sufferers.

PARALYSIS - Loss or impairment of motor function in a part due to lesion of the neural or muscular mechanism; also by analogy, impairment of sensory function (sensory paralysis). In addition to the types named below, paralysis is further distinguished as traumatic, syphilitic, toxic, etc., according to its cause; or as obturator, ulnar, etc., according to the nerve part, or muscle specially affected.

PARASYMPATHETIC NERVOUS SYSTEM - The part of the autonomic nervous system which is responsible for the functioning of nerves, muscles, glands, etc,. when the body is at rest. In contrast to the sympathetic system, whose motto is "fight or flight", the popular phrases for the parasympathetic system are "rest & digest" and "breed and feed". The actions of the sympathetic and parasympathetic systems are essentially complementary and oppositional - in general, what one does, the other undoes.

PARESTHESIA - A burning, tingling sensation often felt in neuritis. Can also refer to total loss of sensation.

PARKINSON'S DISEASE - In a healthy brain, brain cells produce a chemical called dopamine. Dopamine is responsible for relaying messages within the brain that control movement in the human body. When these cells are damaged, the signs of Parkinson’s Disease begin to show. Typically, the signs of Parkinson’s appear slowly, as a subtle tremor in just one hand, for example.

PAROXYSMAL DYSESTHESIA - Spontaneous sharp jabs of pain in the affected region that seem to come from nowhere.

PARTITION COEFFICIENT - a quantitative measure of the lipophilicity of a compound, often a drug. The higher the number, the more fat-soluble the compound is. This is usually reflected in both a faster onset of action and longer duration of action.

PASSIVE TRANSPORT - the movement of molecules or ions across a cell membrane, from an area of higher to lower concentration. This requires no outside energy and occurs spontaneously, due to the gain in entropy.

PATHOLOGICAL - state of disease, not associated with a healthy body or portion thereof. Characteristic of illness.PCA

PATIENT-CONTROLLED ANALGESIA (PCA) - Pain medication given through an IV or epidural catheter. Patients control the dose of medication they take, depending on how much is needed to control the pain. PCA is usually used for patients recovering from intra-abdominal, major orthopedic, or thoracic surgery, and for chronic pain states, such as those due to cancer.

PEPTIDE - a polymer of at least two amino acids; very long such polymers are called proteins.

PERFUSION - 1. the act of pouring over or through, especially the passage of a fluid through the vessels of a specific organ. 2. a liquid poured over or through an organ or tissue.

PERIODIC TABLE - A typical listing of all of the known elements, except that, instead of atomic weights and other constants, the electronegativity value is given for each element.

PERIPHERAL - "Toward the outside", noncentral. In the body, generally refers to parts of the body that are not centrally located, such as the difference between the central and peripheral nervous systems.

PERIPHERAL NERVE STIMULATION - Works in a similar way to spinal cord stimulation, but the lead is placed on the nerve that is causing PNSpain closer to the point of pain, rather than where the nerve exists the spinal column.

PERIPHERAL NERVOUS SYSTEM - The nerves throughout the body that send messages to the central nervous system.

PERIPHERAL NEUROPATHY - People who suffer from mild peripheral neuropathy can have symptoms such as tingling, sensitivity to touch, and numbness, as well a prickling sensation or muscle weakness. Those who have more serious neuropathy can experience symptoms such as an excruciating burning pain, paralysis, muscle wasting, and organ or gland dysfunction.

PERIPHERY - The part of the body away from the center.

PHANTOM LIMB PAIN - Individuals who have had to have a limb amputated often suffer pain that appears to come from the amputated limb. This is termed phantom limb pain. Other sensations can also be present, such as tickling or itching.

PHENOBARBITAL - a member of the barbiturate family of drugs, and the only one still in common use, primarily as an antispasmodic agent. A controlled substance in Schedule C-IV. Compare with phenytoin (Dilantin®).

PHENOL - an acidic organic aromatic alcohol (C6H5OH) with a characteristic odor. Also known as carbolic acid, it is occasionally used as the caustic agent in a chemical sympathectomy. Has been used as a bacteriocide for generations.

PHENOTYPE - the composite of an organism's appearance and function, and is a combination of inherited traits and characteristics and the effect of its environment. Organisms with the same inherited genes (their genotype) can (and often do) appear differently, due to environmental variables and factors.phenytoin

PHENYTOIN - the drug name for Dilantin®, one of the first successful antiepileptic (antiseizure) drugs. It is structurally related to phenobarbital, but possesses no psychoactivity, and thus is not controlled (phenobarbital is a C-IV controlled substance).

PHYSIATRICS - Physical medicine, including physical therapy and rehabilitation techniques. Physiatrists specialize in restoring optimal function to people with injuries to the muscles, bones, tissues, and nervous system (such as stroke victims).

PHYSIATRIST - A doctor who is certified as a specialist in rehabilitation medicine to help disabled people reach their maximum potential. Often coordinates a team of other doctors and health professionals in developing and carrying out a comprehensive rehabilitation plan which extends beyond hospital walls into the patient's family, community, occupation, friends, and ultimate life style. This rehabilitation team may include physical, occupational, and/or speech therapies, nurses and doctors from various specialties, including neurology and orthopedics, psychologists, counselors or social workers, rehabilitation engineers and others.p.t.

PHYSICAL THERAPY - Treatments with manipulation, exercises, massage, heat, cold, stimulators, etc. used to assist recovery and movement of the body after injury or surgery. There are literally dozens of modalities ranging from very rigorous, occasionally painful contact with one's body (e.g., rolfing) to a very gentle, nurturing experience (e.g., Swedish massage).

PHYSICIAN-ASSISTED SUICIDE - Actions by a doctor that help a patient commit suicide. Though the doctor may provide medication, a prescription, or take other steps, the patient takes his/her own life (for instance, by swallowing the pills that are expected to bring about death).

pilomotorPILOMOTOR CHANGES - Changes in the amount of "goose bumps" due to chilling effect on skin, caused by tiny muscles that cause skin hair to stand up.

PLACEBO - Any dummy medication or treatment. Although placebos originally were medicinal preparations having no specific pharmacological activity against a targeted condition, the concept has been extended to include treatments or procedures, especially those administered to control groups in clinical trials in order to provide baseline measurements for the experimental protocol. Compare with nocebo.

PLEXUS - A network or tangle; a general term for a network of lymphatic vessels, nerves, or veins. The one known to most people is the solar plexus, so named for its being the chakra associated with the heavens.

POLAR - can refer to a molecule, bond, and other structures; possesses a negative and positive end. In bonds, it's a function of the difference in electronegativity between the two bonded atoms. There are many degrees of polarity, from totally nonpolar (such as when two identical atoms are bonded to one another, as in oxygen, O2) to ionic, where there is no sharing of valence electrons (as in salt, Na+Cl-).

POLYARTHRITIS - Inflammation of several joints.

POLYMYALGIA RHEUMATICA - A condition characterized by muscle pain and stiffness, fatigue and fever. It is often associated with giant-cell arteritis which is a related but more serious condition.

POLYMYOSITIS - Inflammation of several groups of muscles.

POPPY STRAW - refers to the opium poppy (Papaver somniferum) that has been harvested, dried, and its seeds removed. This is the way that legal crude opium is packaged and distributed. Through careful breeding, poppy straw can contain up to 25% crude morphine while other phenotypes are <1% morphine but high in opioid chemicals which are then chemically modified to produce "semisynthetic" narcotics including hydrocodone, hydromorphone, oxycodone, and several other clinically useful opiates.

PORPHYRIA - not one simple disorder, but refers to a group of at least eight separate disorders. Although each disorder within the classification of porphyria carries with it its own set of unique characteristics, the one common characteristic shared by all disorders within the classification of porphyria is that they all result from the build-up of chemicals known as porphyrins or porphyrin precursors.PTSD

POST-TRAUMATIC STRESS DISORDER (PTSD) - a severe anxiety disorder that can develop after exposure to any event which results in psychological trauma. Symptoms include: recurrent re-experiencing of the trauma, sleep problems, irritability, anger, poor concentration, blackouts, and a phobia of places, people, and experiences that remind the sufferer of the trauma.

KPOTASSIUM - An element (symbol = K) that is in the alkali group of metals. It has an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion (K+) is a strong electrolyte and it plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance. Compare with sodium.

PREGABALIN - aka Lyrica, the first drug specifically indicated for fibromyalgia. Closely related to gabapentin, its efficacy and side-effect profile are highly individual.

PREMENSTRUAL SYNDROME (PMS) - a female malady that occurs in the days or weeks leading up to menstruation. The symptoms may also occur during the beginning of menstruation. The symptoms generally show up roughly 5 to 11 days before a woman starts her period.

PRESCRIPTION - usually refers to an order that a pharmacist dispense and that a patient take certain medications. As medical practice has Rx padbecome increasingly complex, the scope of meaning of the term "prescription" has broadened to also include clinical assessments, laboratory tests, and imaging studies relevant to optimizing the safety or efficacy of medical treatment.

PROKARYOTE - a single-celled organism without a nucleus surrounded by a membrane. Instead, all water-soluble intracellular components (DNA, metabolites, proteins, etc.) are together, all surrounded by the cell membrane.

PROLAPSE - 1. the falling down, or sinking, of a part or viscus; procidentia. 2. to undergo such displacement.

PROSTAGLANDIN - A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.

PROSTATITIS - the inflammation or swelling of the prostate gland. Sometimes, prostatits involves a bacterial infection; however, an infection is not always present. Prostatitis is not associated with prostate cancer nor does it raise the risk of eventually being diagnosed with prostate cancer.

PROTEIN - Polymer of amino acids linked by peptide bonds. The specific sequence of amino acids determines the shape and function of the protein.

PROXIMAL - Closer to the center of the body than another reference point. For instance, the knee is proximal to the ankle. Opposite is distal.

PSORIASIS - an immune-mediated disease that affects an individual’s epidermis or skin. This condition is typically a lifelong condition that does not become resolved over time. There is currently no cure to psoriasis, but various different types of treatment options can help control or mildly lessen the symptoms.

PSYCHIATRIST - A physician (M.D. or D.O.) who specializes in disorders of the mind; some, but not many, also do psychotherapy.

PSYCHOLOGICAL ASSESSMENT - A process that uses information from different sources, such as psychological tests, personal and medical history, and description of current symptoms and problems experienced by either you or by others. As chronic pain involves both your mind and body, a psychological assessment might be performed to help in deciding whether neurostimulation or intrathecal drug delivery is right for you.

PSYCHOLOGIST - A Ph.D. specialist who studies the function of the mind; can be specially licensed to do psychotherapy.

PSYCHOSIS - refers to an abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality". People with psychosis are described as psychotic.

PSYCHOSOMATIC - Designating or of a physical disorder of the body originating in or aggravated by the psychic or emotional processes of the individual.

PSYCHOTROPIC - Exerting an effect upon the mind; capable of modifying mental activity; usually applied to drugs that affect the mental state.

PULMONARY FIBROSIS - a progressive disease that, over a period of time, causes the tissue inside the lungs to become thickened, scarred, stiff and damaged. The medical term used to describe the scar tissue is fibrosis. Although there are other diseases or conditions that can cause fibrosis within the lungs, when there is no other known cause it is called Idiopathic Pulmonary Fibrosis, or IPF.

PULSE - one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. Pulse (or the count of arterial pulse per minute) is equivalent to measuring the heart rate. The average for humans is in the lower 70's.


QUADRIPLEGIA - a form of bodily paralysis, also known as tetraplegia, that is caused by an illness or a sustained injury to a part of the body that results in partial or total loss of the use of the limbs and torso. The loss that occurs is usually sensory and motor, which means that both sensation and control are lost. The main cause for quadriplegia is by any occurred trauma to the brain or the spinal cord.

QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIPS (QSAR) - SAR using sophisticated computer techniques to quantify the effects of substituents, solvent polarity, etc. on the activity of a drug candidate. These very complex calculations are usually executed using supercomputers, since the number-crunching is so intense. Often enables the design of a biologically active molecule with predictable properties, including onset of action, lipophilicity, rate of metabolism, duration of action, and other variables.

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RADIATION TREATMENT - Treatment with x-rays or radionuclides. The most common side effects are tiredness, skin reactions (such as a rash or redness, permanent pigmentation, and scarring) in the treated area, loss of appetite, inflammation of tissues and organs, diarrhea and a decreased number of white blood cells.

RADICULAR - Referring to the nerves originating in the spine.

RADICULITIS - Inflammation of the root of a nerve, particularly of a nerve going to the spinal cord. It is accompanied by excruciating pain along the course of the nerve.

RADICULOPATHY - Disease of the spinal nerves.

RADIOLOGIST - A physician who specializes in the use of X-rays and radioactive substances, both for diagnostic and for treatment purposes.

RAYNAUD'S DISEASE - A disease in which there is chronic constriction and spasm of the blood vessels and digital arteries in the fingers, toes, tip of nose, etc. causing pallor (blanching). It can occasionally lead to gangrene of the affected area.

REBOUND REACTION - A flare-up of symptoms when medication is abruptly terminated.

RECEPTOR - 1. a molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., cell-surface receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and cytoplasmic receptors for steroid hormones. 2. a sensory nerve terminal that responds to stimuli of various kinds.

RECESSIVE TRAIT - In genetics, a trait that must be contributed by both parents in order to appear in the offspring. Recessive traits can be carried in a person's genes without appearing in that person. Compare with dominant trait.

REFERRED PAIN - Pain which is felt some distance from the site of its origin, or at a distance from the trauma that causes nociceptive pain.

REFLEX - An uncontrollable (involuntary) response to a particular stimulation.

REFLEX SYMPATHETIC DYSTOPHY (RSD) - The longest-lasting name for this syndrome, when it was thought that the sympathetic nervous system was always involved. Please see complex regional pain syndrome (CRPS).

REFLEXOLOGY - An alternative treatment with the philosophy that, by applying pressure to certain reflex points on the hands or feet, blood circulation is improved, the body relaxes and organs and glands become balanced. Has never passed a controlled trial.

REFLUX - 1. Flowing in a backward direction, as the flowing of the intestinal contents back to the stomach. 2. To boil a liquid with a mechanism for condensing the vapors back to the liquid, so boiling for hours without losing solvent is possible.

REITER'S SYNDROME - falls within a group of disorders that all cause joint inflammation and are collectively known as “reactive arthritis“. The disorders are referred to as reactive arthritis because they generally develop after an infection in another area of the body.

REMISSION - A reduction in all or the majority of symptoms in a medical condition. Differentiated from "cure" in that remissions are prone to fluctuations between full-blown illness and being symptom-free, with a myriad of different partial remissions depending on the individual and the disease.

RESPIRATORY RATE - The number of breaths per minute. The normal adult inhales approximately twenty times per minute.

RESTLESS LEGS SYNDROME (RLS) - also known as Wittmaack-Ekbom's syndrome, a condition that is characterized by an irresistible urge to move one's body to stop uncomfortable or odd sensations.

RHABDOMYOLYSIS - a dangerous syndrome resulting from a prolonged, intense muscle spasm. The muscle cells begin to break, and the resulting proteins tend to block (blind) the kidneys, resulting in possible acute renal failure. This is a life-threatening condition which must be surgically treated asap, or loss of the limb can result. Cf. compartment syndrome.

RHEUMATOID ARTHRITIS - a chronic systemic autoimmune disease that primarily involves the joints. RA causes damage mediated by cytokines, chemokines, and metalloproteases. A very serious form of arthritis for which good drugs are not yet available. Compare with osteoarthritis.

RHEUMATOLOGIST - A specialist in diseases involving the joints, particularly arthritic conditions. Usually treats FM patients.

RHIZOTOMY - Surgery to cut the roots of spinal nerves, carried out to relieve incurable pain.

RIBOFLAVIN - Nutritional factor found in milk, eggs, malted barley, liver, kidney, heart, and leafy vegetables, aka vitamin B2. The richest natural source is yeast. It occurs in the free form only in the retina of the eye, in whey, and in urine; its principal forms in tissues and cells are as FMN and FAD.

ROMBERG - Inability to keep one's balance when standing with eyes closed.

ROSACEA - best defined as a chronic inflammatory-based skin condition that primarily tends to affect adults. This condition causes redness in a patient's face and is capable of producing small, red, pus-filled bumps or pustules. If left untreated, rosacea tends to be a very progressive condition that eventually will become worse over time.

ROTATOR CUFF- Comprised of four muscles in the shoulder area that can be irritated by overuse. The muscles are the supraspinatus (most commonly injured), infraspinatus, teres minor, and subscapularis.

ROTATOR CUFF IMPINGEMENT SYNDROME - A microtrauma or overuse injury caused by stress, and the four stages are: 1) Tendentious with temporary thickening of the bursa and rotator cuff; 2) Fiber dissociation in the tendon with permanent thickening of the bursa and scar formation; 3) A partial rotator cuff tear of less than 1 cm.; and 4) A complete tear of 1 cm. or more.

Rx - medical shorthand for "prescription".


SALICYLATE DRUGS - Medications particularly useful in relieving pains in muscles and joints, as well as reducing fever. The best-known example is aspirin. The most common serious side-effect is GI irritation, especially the stomach.

SALINE - Salty; of the nature of a salt; containing a salt or salts.

SCHIZOAFFECTIVE DISORDER - An illness manifested by an enduring major depressive, manic, or mixed episode along with delusions, hallucinations, disorganized speech and behavior, and negative symptoms of schizophrenia. In the absence of a major depressive, manic, or mixed episode, there must be delusions or hallucinations for several weeks.

SCHIZOPHRENIA - a mental disorder that presents with a number of sometimes confusing symptoms. The characteristics that define schizophrenia, while often accompanied by many other issues, are emotional disturbances and disturbances in thought processes.  It can lead to withdrawing oneself from others, lack of employability, homelessness and hospitalization.

SCIATIC NERVE - Major nerve that carries impulses for muscular action and sensations between the low back and thigh and the lower leg. It is the longest nerve in the body.

SCIATICA - A condition in which there is severe pain in the lower back and down the back of the thigh and leg along the route traveled by the sciatic nerve. It is associated with an inflammation of the sciatic nerve and may lead to numbness, tingling, and wasting of the muscles supplied by the sciatic nerve.

SCLERODERMA - A rare, progressive connective tissue disorder involving thickening and hardening of the skin and connective tissue. There are a number of forms of scleroderma with some forms being systemic (involving internal organs).

SCLEROSING TENOSYNOVITIS - An inflammation and overgrowth of a tendon sheath causing intense pain, most often seen in the wrist near the base of the thumb.

SCOLIOSIS - a medical condition that causes the spine to become curved from side to side. If viewed from the back, a person who suffers from scoliosis will have a spine that looks more like a “C’ or an “S” instead of a straight line. Scoliosis can be congenital in nature, meaning is was caused by a defect present at the time of birth.

SEDATIVE - 1. allaying activity and excitement. 2. an agent that allays excitement.

SEIZURE - episode of disturbed brain function that cause changes in attention or behavior, which are caused by abnormally excited electrical signals in the brain. The severity of symptoms can vary greatly, from staring spells to violent convulsions and loss of consciousness.

SELENIUM - An element with the atomic symbol Se, atomic number 34, and atomic weight 78.96. It is an essential micronutrient for mammals and other animals but is toxic in large amounts. Selenium protects intracellular structures against oxidative damage. It is an essential component of glutathione peroxidase.

SEPTIC - Produced by or due to decomposition by microorganisms; putrefactive, widely infected.serotonin

SEROTONIN - An important neurotransmitter, found in the blood, with a huge number of effects; these include vasoconstriction,movements and peristalsis of the GI system, and a feeling of wellness and calm. Other important neurotransmitters include dopamine and norepinephrine. Lowered levels of serotonin were the first involving neurotransmitters in treating depression, and the second "S" in "SSRI" stands for serotonin (the phrase is "selective serotonin reuptake inhibitor".

SHINGLES - A disease caused by a virus, characterized by a painful skin rash with blisters in a limited area on one part of the body, often in a stripe or patch that follows the path of the involved nerve.

SHORT TERM MEMORY - The ability to remember recent events.

SHOULDER-HAND SYNDROME - Pain, stiffness and numbness, leading to shrinking of the muscles; all in the shoulder, arm and hand. Thought to be brought on by the lack of proper function of the nerves supplying this area of the body.

SIDE-EFFECTS - Unwanted, unanticipated, and/or unavoidable (as opposed to therapeutic) effects of a drug or treatment.

SIGN - an indication of a disease state that is observable to another person, such as coughing, fever, hives, rapid pulse; compare to symptom.

SINUSITIS - Inflammation in the sinuses. It happens when the body responds to an infection. The infection may be fungal, viral or bacterial. It may also occur in response to allergies or to injuries to the sinuses or nose. It can happen to any person at any age and is a common side effect of infection.

SITE OF LOSS - any location in the body that a drug can be found except its target receptor. Examples include protein binding, metabolism, excretion, dissolution in body fat, and many others.

SJOREN'S SYNDROME - a medical disorder that directly affects a patient's immune system and is identified by its two most common symptoms — dry eyes and extremely dry mouth. Sjogren's syndrome often accompanies and works in unison with other immune-system disorders, such as rheumatoid arthritis and lupus.

SNRI - Selective norepinephrine (NE) reuptake inhibitor, a class of antidepressants. NE is the primary neurotransmitter of the sympathetic nervous system (SNS). Compare with SSRI.

SODIUM - a chemical element with symbol Na (from Latin: natrium) and atomic number 11. It is a soft, silver-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. Sodium is an essential nutrient that regulates blood volume, blood pressure, osmotic equilibrium and pH; the minimum physiological requirement for sodium is 500 milligrams per day. It is the main cation (as Na+) in intercellular fluid (plasma, blood, etc.). Compare with potassium.

SPASM - An abrupt and forceful contraction of a muscle usually associated with marked pain or discomfort. Can last from less than a second to many hours or longer.

SPASTICITY - stiffness in a muscle or an increase in muscle tone that is considered abnormal. It typically takes place when nerve damage inhibits the ability to control muscles. It most often associated with multiple sclerosis. However, it can also take place with cerebral palsy, ALS, stroke, when a spinal cord is damaged and a number of other injuries and disorders.

SPECTRUM - A charted band of wavelengths of electromagnetic vibrations obtained by refraction and diffraction. By extension, a measurable range of activity, such as the range of bacteria affected by an antibiotic (antibacterial spectrum) or the complete range of manifestations of a disease.

SPINAL COLUMN - The spinal column or spine supports the skeleton, and surrounds and protects the delicate spinal cord and nerves. It is made up of 33 bones called the vertebrae.

SPINAL CORD - The spinal cord is made up of nerve fibers and is the central route along which all pain signals travel to and from the brain. The spinal cord is protected by the spinal column.

SPINAL CORD STIMULATION (SCS) - A method of pain relief which uses a small neurostimulation system that is surgically placed under the skin to send mild electrical impulses to the spinal cord. The electrical impulses are delivered through a lead (a special medical wire) that is also surgically placed (see diagram to the right). These electrical impulses block the signal of pain from reaching the brain.

SPINAL STENOSIS - A medical condition associated with chronic pain in which the canal containing the spinal cord narrows and compresses the spinal cord and nerves. This is usually due to the natural aging process but can also be caused by lumbar disc herniation, osteoporosis or cancer.

SPONDYLITIS - Inflammation of the vertebrae.

SPRAIN - A partial or complete tear of a ligament.

SSRI - Selective serotonin reuptake inhibitor, a class of antidepressants. Works by blocking the removal of serotonin from the cleft between neurons, so that the serotonin produced by the brain accumulates, such that the "background" concentration of serotonin in the brain increases. Compare with SNRI.

STELLATE GANGLION BLOCK - a nerve blockade, established with a long-acting local anesthetic like bupivicaine, at the stellate ganglion, which is in the thorax. It is usually used for upper-extremity CRPS.

STENOSIS - Narrowing or stricture of a duct or canal.

STIMULANT - 1. producing stimulation; especially producing stimulation by causing tension on muscle fiber through the nervous tissue. 2. an agent or remedy that produces stimulation.

STIMULUS - Something which stimulates (arouses action) in the muscles, nerves or other excitable tissue and results in a specific reaction.

STOMACH - An organ of digestion situated in the left upper quadrant of the abdomen between the termination of the esophagus and the beginning of the duodenum.

STRAIN - Injury resulting from a pull or torsion to the muscle or tendon that causes various degrees of stretch or tear to the muscle or tendon tissue.

STROKE - A condition caused by a lack of oxygen to the brain which can lead to a loss in ability to move a part or area of the body. Can be hemorragic, in which blood leaks into the brain, or ischemic, where a blood clot blocks blood flow to the brain.

STRUCTURE-ACTIVITY RELATIONSHIPS (SAR) - the correlation of various analogs of a drug with their biological actions. For instance, a chlorine atom in a certain position might give a compound unneeded toxicity, whereby a fluorine atom in the same position might remove the toxic side-effect. Can be done quantitatively using advanced computational techniques, often utilizing supercomputers, called Quantitative SAR, or QSAR.

SUBCUTANEOUS - Underneath the skin; also a common injection technique.

SUBLUXATION - A slight dislocation of a bone or joint; the term is particularly favored by chiropractors.

SUDECK'S ATROPHY - Degeneration of bone following an injury. Also, an early name for CRPS/RSD.

SUDOMOTOR CHANGES - Increased or decreased sweating.

SUMATRIPTAN - A serotonin agonist that acts selectively at 5HT1 receptors. It is used in the treatment of migraines.

SUPPOSITORY - A small plug of medication designed to melt at body temperature within a body cavity other than the mouth, usually the rectum or vagina.

SYMPATHECTOMY- Cutting or otherwise destroying certain nerves in the SNS in an attempt to stop the unrelenting pain that is characteristic of CRPS/RSD. The nerve(s) can be physically cut or destroyed by chemical agents like an alcohol or phenol. It is almost universally unsuccessful, since, even if there is initial pain relief, it almost invariably returns with a vengeance. A common synonym is ablation.

SYMPATHETICALLY INDEPENDENT PAIN (SIP) - pain that no longer can be affected by most drugs or procedures designed to block or lessen pain which is mediated by the sympathetic nervous system (SNS). It is most easily diagnosed by attempting a nerve block of some kind, usually epidural; SIP does not respond to these procedures.

SYMPATHETICALLY MAINTAINED PAIN (SMP) - pain is very responsive to local pain reduction efforts, especially sympathetic nerve blocks. Most pain in RSD is sympathetically maintained until the disease reaches quite late stages.

SYMPATHETIC NERVOUS SYSTEM (SNS) - The part of the autonomic nervous system which is responsible for the functioning of nerves, muscles, glands, etc,. when the body is at high alert, as if there is danger nearby. This is the origin of the main motto for the SNS, called "fight or flight". The actions of the sympathetic and parasympathetic systems are essentially complementary - what one does, the other undoes.

SYMPATHOMIMETIC - a process or, more usually, a compound that acts to stimulate the sympathetic nervous system (SNS). Similar meaning to adrenergic.

SYMPTOM - Where a difference from normal function or feeling is noticed by you but not by anyone else, including a physician, such as fatigue, pain, dizziness, itching, etc. A symptom can be a signal of disease or another abnormality. Compare with sign.

SYNCOPE - Fainting.

SYNDROME - A group of symptoms and signs which, when appearing simultaneously, form a definite pattern of a specific condition, disease, or abnormality.

SYRINGOMYELIA - a neurological disorder where the patient develops a fluid-filled cavity, also known as a syrinx which often becomes lodged in the neck region. Over time, the cyst may enlarge, causing chronic pain, weakness and stiffness throughout the body.

SYSTEMIC - Pertaining to or affecting the body as a whole.

SYSTOLIC BLOOD PRESSURE - The force with which blood is pumped when the heart muscle is contracting. It is the upper, larger number in reporting b.p. data, so that for 120/80, 120 is the systolic pressure. The lower number is the diastolic pressure, when the heart's ventricles are relaxed.

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TACHYKININS - A family of biologically active peptides sharing a common conserved C-terminal sequence, - Phe-X- Cly- Leu- Met-NH2, where X is either an aromatic or a branched aliphatic amino acid. Members of this family have been found in mammals, amphibians, and mollusks. Tachykinins have diverse pharmacological actions in the central nervous system and the cardiovascular, genitourinary, respiratory, and gastrointestinal systems, as well as in glandular tissues. This diversity of activity is due to the existence of three or more subtypes of tachykinin receptors.

TARDIVE DYSKINESIA (TD) - a neurological movement disorder that causes repetitive and involuntary movements of the lower face and limbs, and often has symptoms similar to Parkinson's Disease and Tourette's Syndrome.  TD is a serious side-effect caused by certain medications, especially antipsychotics (including haloperidol, fluphenazine, trifluoperazin, cinnarizine, flunarizine, metoclopramide and reglan) and can become permanent even after stopping the use of such medications.

TARLOV CYSTS - also known as perineurial cysts, are sacs filled with cerebrospinal-fluid (CSF) located along the spinal cord. These cysts most commonly affect nerve roots toward the lower end of the spine. The cysts are found incidentally through MRI tests conducted for other purposes.

TARSALS - Group of six bones of the foot consisting of the calnavicular, talus, cuboid, and three cuneiform bones.


TCA - Tricyclic antidepressant - the most common structural type of antidepressant. Refers to its structure having three carbon rings as its major feature. See amitriptylene in the left diagram, with its three large rings.

TELAGIA - Pain radiating to another part of the body; referred pain. TMJ

TEMPOROMANDIBULAR JOINT (TMJ) - The junction of the lower jawbone (the mandible) and the temporal bone, located just in front of the ear. A common area to become inflamed during times of high stress.

TENDER POINTS - Areas on the body which hurt where pressed, but do not refer pain elsewhere. They usually occur in pairs on various parts of the body, therefore usually equally distributing the pain on both sides of the body.

TENDINITIS - Inflammation of the tendon and/or the tendon sheath, caused by chronic overuse or sudden injury.

TENDON - Tissue that connects muscle to the bone.

TENOSYNOVITIS -an inflammatory condition which affects the lining outside of tendons. Because tendons connect bone to muscle, this can occur anywhere there is bone and muscle. However, it tends to affect the joints, particularly those of the feet, wrists and hands. The condition can be caused by injuring the tendon lining or by infection. It causes pain and swelling when caused by injury.

TESTOSTERONE - a messenger for the body. Like most hormones, it is involved in several different body processes both directly and indirectly. As levels of testosterone decline, various symptoms may arise. Men may experience fatigue, weight gain, loss of libido (interest in sex), decreased mental sharpness, loss of motivation, mood swings or irritability and declining muscle mass. Endogenous production of testosterone slows dramatically when a man takes opioids for an extended period.

TETRAHYDROCANNABINOL (THC) - the psychoactive principle of marijuana, a highly lipophilic drug, which explains why it lasts in the body for such a long time.

THALAMUS - Either of two large, ovoid masses, consisting chiefly of grey substance, situated one on each side of and forming part of the lateral wall of the third ventricle of the brain. It is divided into two major parts, dorsal and ventral, each of which contains many nuclei.

THEBAINE - A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects. At high doses, it causes convulsions similar to strychnine poisoning. Its value is that is easily converted to many useful drugs, including oxycodone, oxymorphone, naloxone, and buprenorphine.

THENAR REGION - The palm of the hand, especially that region located adjacent to the base of the thumb.

THERAPEUTIC INDEX - the dose of a drug between the minimal effective dose (ED) and the toxic dose (TD). For safe drugs, this is a wide window; more dangerous agents often have very narrow therapeutic indices.

THERMODYNAMICS - a branch of physics concerned with heat and temperature and their relation to energy and work. It defines macroscopic variables, such as internal energy, entropy, and pressure, that partly describe a body of matter or radiation. It states that the behavior of those variables is subject to general constraints, that are common to all materials, not the peculiar properties of particular materials. These general constraints are expressed in the four laws of thermodynamics.thermography

THERMOGRAPHY - A technique for measuring the heat given off by a particular organ or region of the body. A thermogram is extremely sensitive and records small temperature changes. While these will show RSD in many cases, a negative result does not mean the patient does not have RSD.

THORACIC - Referring to the chest.

THORACIC OUTLET SYNDROME - Condition due to compromise of blood vessels or nerve fibers between the armpit (axilla) and base of the neck.

THROMBOSIS - The formation, development, or presence of a thrombus (blood clot).thrombosis

THYROIDITIS - The thyroid is located at the front of the neck, but thyroiditis symptoms may not be limited to this area. That is because the thyroid is part of the endocrine system. When caused by another thyroid condition or when serious, thyroiditis can affect the body in various ways. Thyroiditis can be caused by infections and viral illnesses.

THYROXINE - An amino acid of the thyroid gland which exerts a stimulating effect on thyroid metabolism.

TIBIA - Larger of the two bones of the lower leg and is the weight-bearing bone of the shin. Adjacent to the smaller fibula bone.

TIC DOULOUREUX - or trigeminal neuralgia is a nerve disorder that affects the face. It is a stand-alone condition (idiopathic tic douloureux) and can also be a symptom of other conditions, such as multiple sclerosis. The symptoms of tic douloureux originate in the trigeminal nerve. Pressure on that nerve can cause the symptoms as well as damage.

TINNITUS - The symptoms of tinnitus include ringing, whooshing, roaring, hissing, chirping, buzzing or roaring in the ears. This can occur with a sensation of other sounds being canceled out.

TOLERANCE - a phenomenon or adaptation of the body over a period of time in which one or more effects of a drug become less with repeated use at the same dose (many patients call this becoming “immune” to the drug). For example, a person might feel drugged after the first pain pill; but with continued use, a person might require several pills to feel anything. With analgesics, the concern is that the individual will build up tolerance to the drug and therefore require more medication to achieve results. Unfortunately, in many cases, increasing doses of medications may lead to increased or unacceptable side effects (such as respiratory depression, for opioids. Analgesic tolerance is not addiction.

TOMOGRAPHY - The recording of internal body images at a predetermined plane by means of the tomograph; called also body section roentgenography.

TOPICAL - Pertaining to a particular surface area, as a topical anti-infective applied to a certain area of the skin and affecting only the area to which it is applied.

TOURETTE'S SYNDROME - The symptoms are known as tics or vocalizations, though they differ even among the individual types. Tics can range from simple involuntary blinking or shrugging to twisting. In complex tics, several movements can occur at the same time. For example, an individual with Tourette's syndrome might blink while jumping.

TOXICITY - The quality of being poisonous, especially the degree of virulence of a toxic microbe or of a poison.

TOXICOLOGY - The scientific discipline concerned with understanding the mechanisms by which chemicals produce noxious effects on living tissues or organisms; the study of the conditions (including dose) under which exposure of living systems to chemicals is hazardous.

TRANS ISCHEMIC ATTACKS (TIA) - A temporary paralysis, numbness, speech difficulty or other neurologic symptoms that start suddenly and recovers within 24 hours and is caused when the nerves clamp down on the veins and restrict the blood flow to the heart, brain and other organs.

TRANSPLANTATION - The grafting of tissues taken from the patient’s own body or from another.

trichotillomaniaTRICHOTILLOMANIA - also known as compulsive hair pulling, which essentially sums up the disorder. Medical marijuana may be prescribed for this and other compulsive behaviors, though trichotillomania is more specific than other compulsive disorders for which medical marijuana is prescribed such as obsessive-compulsive disorder. Trichotillomania affects only the sufferer. These individuals will compulsively pull at their own hair until they experience unnatural hair loss.  Individuals with trichotillomania typically present with symptoms before they turn 17.

TRIGEMINAL NEURALGIA - Tenderness and swelling of the trigeminal nerve (the fifth cranial nerve). It causes bouts of intense, lightning pain in the lips, eye area, nose, scalp, forehead, gums, cheek and chin on one side of the face. A less common form of the disease causes a more constant, dull, burning or aching pain.

TRIGGER FINGER - A dislocation of a tendon so that the flexion or extension of a finger is temporarily halted. trigger points

TRIGGER POINT - A hypersensitive area or site in muscle or connective tissue, usually associated with myofascial pain syndrome. When touched or pressed they bring on a painful response and referred pain. They can also be felt as painful lumps of hardened fascia.

TRIPHASE BONE SCAN - Please see Bone Scan.

TROPHIC - pertaining to, or involving, nutrition.

TUMOR - An abnormal growth that may be benign (non-cancerous) or malignant (cancerous).

Tx - medical shorthand for "treatment".


ulnaULNA - Forearm bone that runs from the tip of the elbow to the little finger side of the wrist.

ULNAR NERVE -A major nerve of the upper extremity. In humans, the fibers of the ulnar nerve originate in the lower cervical and upper ultrasoundthoracic spinal cord (usually c7 to t1), travel via the medial cord of the brachial plexus, and supply sensory and motor innervations to parts of the hand and forearm.

ULTRASOUND - A type of imaging technique which uses high-frequency sound waves to non-invasively visualize soft tissue; primary use is in fetal development.


valgusVALGUS - The turning out of the foot.

VASCULAR SYSTEM - Blood vessel system, circulatory system. blood system

VASOCONSTRICTION - The narrowing and contraction of blood vessels.

VASOCONSTRICTOR - a substance or process that causes vasoconstriction, i.e., a narrowing of blood vessels, which impedes the free flow of blood through the vessels.

vasodilationVASODILATATION - A synonym for vasodilation; the enlargement of blood vessels, usually via relaxation of the surrounding musculature.

VASOMOTOR MECHANISM - That which regulates the contraction or dilation of blood vessels. Vasomotor changes may produce a sensation of coolness or warmth, depending on whether the vessels are contracted or dilated, respectively.

VASOSPASM - Marked contraction and narrowing of a blood vessel or a segment of a blood vessel.

VENTRAL - 1. pertaining to the belly or to any center. 2. denoting a position more toward the belly surface than some other object of reference; same as anterior in human anatomy.

VERTEBRAE - The 33 bones that comprise the spinal column.vertigo

VERTIGO - Dizziness, especially the feeling that one's surroundings are whirling. Often accompanied by nausea and/or vomiting, this is the feeling of motion sickness.

VIRAL HEPATITIS - a dangerous condition that can require long-term treatment, viral hepatitis is an inflammation of the liver caused by several viruses. Five viruses specifically cause hepatitis. These are hepatitis A, B, C, D and E. However, the hepatitis viruses are not the only viruses that can cause this condition.

VOLAR - Pertaining to the palm or sole surfaces.


WASTING SYNDROME - the progressive involuntary weight loss seen in patients with debilitating medical conditions such as HIV/AIDS, cancer, tuberculosis ,and more.  Symptoms include profound involuntary weight loss of greater than 10% of baseline body weight, chronic diarrhea, chronic weakness and fever. whiplash

WHIPLASH - a painful condition caused by rapid extension and flexion of the neck. In other words, it is pain caused by the head jerking forward and back very quickly.

WITHDRAWAL (DRUG) - A syndrome that might occur when a medication that has been used regularly to treat pain is no longer used, or when the dose is decreased. Showing symptoms of withdrawal does not mean that a patient is addicted to his/her pain medication; it means that tolerance has developed - a physiological adaptation made by the body to the ongoing presence of the drug.

WITTMAACK-EKBOM'S SYNDROME - A synonym for restless legs syndrome (RLS).

WRITERS' CRAMP - Writer's cramp goes by many names; scrivener's palsy, mogigraphia and hand dystonia are a few others. It is essentially cramping or spasming in the hands, forearms or fingers. While writer's cramp gets its name from individuals who write, as the condition can affect them, it can occur with any repetitive fine motor tasks.



XANAX - the main brand name of alprazolam, a widely-prescribed benzodiazepine.

XENOBIOTIC - a substance from outside the body; compare with endogenous.

x-rayX-RAY - An imaging technique used in hospitals that shows up abnormalities in bones and certain body tissues.


YOGA - A system of physical and mental exercises designed to help achieve the goal of living with good health and peace of mind. Yoga can relieve chronic pain in some people.

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