Directory of Physicians and Dentists

Aaron's Rod:  (Used as a symbol for medicine.) A rod (walking stick) with one serpent twined around it, thus differing from Mercury's Caduceus (also used as a symbol of medicine), which has two serpents twined about it. The allusion is to the rod God gave to Moses and his brother Aaron with which to perform miracles and free the Israelites from bondage in Egypt. In the first miracle the rod changed into a serpent in front of Pharaoh. (Unfortunately, Pharaoh didn't give a rip.)

Abacterial thrombotic endocarditis:  Lesions inside the heart occurring with blood clots and inflammation of the wall of the heart in the terminal stages of many chronic infectious and wasting diseases. Synonyms are nonbacterial thrombotic endocarditis, cachectic endocarditis, terminal endocarditis, and thromboendocarditis.

Abadie's sign of tabes dorsalis:  Insensibility to pressure on the Achilles tendon. (Joseph Abadie: French neurosurgeon, 1873-1946) (Achilles: Mythical Greek warrior, vulnerable only at the heel). Tabes: Progressive emaciation of the body, accompanied with fever, with no discoverable cause. Tabes dorsalis: A condition that results from the destruction of the dorsal columns in the spinal cord which are responsible for proprioception (position sense). Loss of position sense causes severe gait and leg ataxia (balance and motor control problems). Tabes dorsalis can be the result of spinal cord injury or infection with syphilis. Tabes dorsalis results in a staggering wide-based gait, postural instability, pain and paresthesias. Tabes dorsalis is a classical sign of late stage syphilis, a condition which was once common but now rarely seen since the discovery of penicillin and methods to detect early syphilis.

Abasia:  Lack of motor or muscular coordination in walking.

Abasia trepidans:  Difficulty standing (abasia) due to trembling of the lower limbs.

Abbokinase:  A thrombolytic (clot busting) agent which works by activating the body's own fibrinolytic system by activating the production of plasmin from plasminogen. Plasmin is an enzyme which degrades fibrin clots and fibrinogen, as well as several other protein clotting factors.

Abbott's method:  A method of treatment of scoliosis (a curvature of the spine) by use of a series of plaster jackets applied after partial correction of the curvature by external force.

Abdomen:  The portion of the body which lies between the thorax and the pelvis. It contains a cavity (abdominal cavity) separated by the diaphragm from the thoracic cavity above and by the plane of the pelvic inlet from the pelvic cavity below and lined with a serous membrane, the peritoneum. This cavity contains the abdominal viscera and is enclosed by a wall formed by the abdominal muscles, vertebral column and the iliac bones on each side.

Abdominal angina:  A dull, cramping centralized abdominal pain that occurs 15-30 minutes after a meal, associated with ischemic bowel disease, and diagnosed with mesenteric arteriography.

Abdominal aortic aneurysm:  A weakened distended area in the wall of the abdominal aorta, more common in those who suffer from atherosclerosis. Rupture of an abdominal aortic aneurysm is usually fatal.

Abdominal apoplexy:  Bleeding, blood clot, or embolus in the vessels (arterial system) which supplies the intestine. Usually acutely painful.

Abdominal ballottement:  Examination of the abdomen by palpation to detect excessive amounts of fluid (ascites) by causing organs to bob up and down in the fluid milieu.

Abdominal dropsy:  An effusion and accumulation of serous fluid in the abdominal cavity, also called ascites.

Abdominal fistula:  A tract leading from one of the abdominal viscera to the external surface.

abdominal migraine:  Migraine in children accompanied by paroxysmal abdominal pain. This must be distinguished from similar symptoms requiring surgical attention.

abdominal muscle deficiency syndrome:  Congenital absence (partial or complete) of abdominal muscles, in which the outline of the intestines is visible through the protruding abdominal wall

abdominal paniculectomy:  A surgical procedure to remove fatty tissue and excess skin from the lower to middle portions of the abdomen. This procedure is indicated in some individual's who have lost considerable weight resulting in loose hanging folds of skin in the abdominal area. Recovery is in 2-4 days.

abdominal pregnancy:  The implantation and development of the ovum in the peritoneal cavity, usually secondary to an early rupture of a tubal pregnancy; very rarely, primary implantation may occur in the peritoneal cavity.

abdominal respiration:  Breathing effected mainly by the action of the diaphragm to the relative exclusion of the chest muscles.

abdomino-jugular reflex:  An elevation of venous pressure visible in the jugular veins and measurable in the veins of the arm, produced in active or impending congestive heart failure by firm pressure with the flat hand over the abdomen. Often called hepato-jugular reflex when pressure is exclusively over the liver.

abdominocentesis:  Paracentesis (aspiration of fluid using a needle) of the abdomen.

abdominocyesis:  Pregnancy with implantation in the abdominal cavity.

abdominoplasty:  A procedure to remove fatty tissue, excess skin and tighten the muscular and fascial structures of the lower to middle portions of the abdomen.

abdominous:  Having a protuberant belly; pot-bellied.

abduct:  To move away from the median plane.

Abelson murine leukemia virus:  A retrovirus belonging to the Type C retrovirus group subfamily (family Oncovirinae) which is associated with leukemia and produces in vitro transformation of mouse cells. (murine Pertaining to mice.) (in vitro In a test tube as distinguished from in a body which is in vivo.)

abembryonic:  The area of the blastocyst opposite the region where the embryo is formed. In other words, the location of the developing placenta.

abenteric:  Away from the intestine, said of a morbid process occurring elsewhere that would normally occur in the intestine.

aberrant artery:  Artery having an unusual origin or course.

abiological:  Pertaining to the study of inanimate things.

abiotic:  Refers to nonliving objects, substances or processes.

abiotic stress:  Nonliving environmental factors (such as drought, extreme cold or heat, high winds) that can have harmful effects on animals or plants.

abiotic transformation:  Any process in which a chemical in the environment is altered by non-biological mechanisms (such as by exposure to sunlight).

abirritant:  A medicine that diminishes irritation.

ablate:  To remove, usually by cutting. at surgery; e.g. a tumour can be "ablated."

ablepharia:  Congenital absence, partial or complete, of the eyelids; recessive inheritance.

ablutomania:  A morbid preoccupation with thoughts about cleanliness, exhibited by obsessive washing.

ABO antigens:  A system of genetically determined antigens (proteins) located on the surface of the erythrocyte. Blood type classifications are derived from these proteins.

ABO blood group:  The major human blood type system which describes the oligosaccharide glycoprotein antigens found on the surface of human blood cells. According to the type of antigen present, a person may be assigned a blood type of A, B, AB or O. A second type of antigen, the Rh factor, renders a positive or negative blood type. The ABO blood group system is important because it determines who can donate blood to or accept blood from whom. Type A or AB blood will cause an immune reaction in people with type B blood and type B and AB blood will cause a reaction in people with type A blood. Conversely, type O blood has no A or B antigens, so people with type O blood are universal donors. And since AB blood already produces both antigens, people who are type AB can accept any of the other blood types without suffering an immune reaction. They are termed universal recipients.

ABO hemolytic disease of the newborn or erythroblastosis fetalis:  due to maternal-fetal incompatibility with respect to an antigen of the ABO blood group; the fetus possesses A or B antigen which is lacking in the mother, and the mother produces immune antibody which causes hemolysis of fetal red blood cells.

ABO incompatibility:  A type of blood incompatibility, found rarely. Transfusion reactions may occur as a result of such incompatibility

aborad:  In a direction away from the mouth; opposite of orad.

aborticide:  The act of destroying a fetus in the womb; feticide.

abortifacient:  A drug or compound that induces the expulsion of an embryo or foetus.

abortus:  Any product (or all products) of an abortion.

abortus bacillus:  Brucella abortus A species of the genus brucella whose natural hosts are cattle and other bovidae. Other mammals, including man, may be infected. Abortion and placentitis are frequently produced in the pregnant animal.

aboulia:  1. Loss or impairment of the ability to perform voluntary actions or to make decisions. 2. Reduction in speech, movement, thought, and emotional reaction; a common result of bilateral frontal lobe disease. Synonym: abulia. Origin: G. A-loss or absence + boule, will

abrachia:  Congenital absence of arms.

abreact:  1. To show strong emotion while reliving a previous traumatic experience. 2. To discharge or release repressed emotion.

abreaction:  A process in psychotherapy in which the patient is "desensitised" to emotionally painful, often forgotten (repressed) memories by recalling and reacting to them in the "safety" of the treatment setting.

abruptio placentae:  This is the premature separation of the placenta, i.e. Separation of the placenta from the site of implantation on the uterus before the delivery of the fetus. It is a life threatening condition for the foetus and occurs about 1 in 500 to 750 deliveries.

absence seizure:  A type of seizure that in contrast to the grand mal seizure, is noted for its brevity and degree of loss of awareness (brief staring spell) accompanied by minimal motor manifestations. A common form of childhood epilepsy.

absent state:  The semiconscious state associated with an epileptic attack.

absolute agraphia:  Agraphia (inability to write) in which not even unconnected letters can be written.

absolute alcohol:  pure, anhydrous (containing no water) alcohol,

absolute glaucoma:  The final stage of blindness in glaucoma.

absolute zero:  The lowest possible temperature (0 Kelvin, -273.15 degrees Celsius, -459.67 degrees Fahrenheit). at this temperature, all molecular motion stops.

absolutist:  One who believes that it is possible to realize a cognition or concept of the absolute.

absorbable surgical suture:  A surgical suture material prepared from a substance that can be digested by body tissues and is therefore not permanent.

absorptive cells of intestine:  Cells on the surface of villi of the small intestine and the luminal surface of the large intestine that are characterized by having microvilli on their surfaces.

abstinence syndrome:  A constellation of physiologic changes undergone by persons who have become physically dependent on a drug or chemical due to prolonged use at elevated doses, but who are abruptly deprived of that substance.

acanthamoeba:  A microscopic organism, an amoeba, found in soil, dust and fresh water (lakes, rivers, hot springs and hot tubs). Infection can have dire consequences Lungs, eye, skin and brain can be affected. Brain involvement is fatal.

acapnia:  Less than the normal level of carbon dioxide in the blood. The opposite of hypercapnia. It comes from the [Greek ”a-” meaning ”without“ + ”kapnos“ meaning ”smoke“ so acapnia literally means ”smokeless“ referring to carbon dioxide which is a principal part of smoke.]

accessory nerve:  The accessory nerve is the eleventh cranial nerve. and supplies the sternocleidomastoid and trapezius muscles. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.

accessory placenta:  An extra placenta separate from the main placenta. The placenta is the organ joining the mother and fetus, the organ that permits the provision of oxygen and nutrients to the fetus and the release of carbon dioxide and waste products from the fetus to the mother. The placenta and the fetal membranes are the afterbirth.

Acclimatization to altitude:  Altitude sickness is caused by going too high too fast. A healthy cardiovascular system can adapt to decreased oxygen concentration a process known as acclimatization. Changes take place in the body to allow it to operate with decreased oxygen: (1) Depth of respiration increases, (2) Pressure in the pulmonary arteries increases, forcing blood into portions of the lung which are normally not used at sea level, (3) More red blood cells to carry oxygen, (4)We make more of a specific substance (called 2,4-DPG) that facilitates the release of oxygen from hemoglobin to the body tissues. Acclimatization generally takes 1 to 3 days at a given altitude. For example, if a person hikes to 10,000 feet (3,048 meters) and spends several days at that altitude, her or his body acclimatizes to 10,000 feet (3,048 meters). If the person then climbs to 12,000 feet (3,658 meters), the body needs to acclimatize once again and it takes another 1 to 3 days.

Accommodation:  In medicine, the ability of the eye to change its focus from distant to near objects (and vice versa). This process is achieved by the lens changing its shape. Difficulty performing this feat usually sets in around age 45-55 and is known as "presbyopia," literally old vision. Old vision is corrected with reading glasses which replace the lens adjustment made in younger eyes. People who have myopia (nearsightedness) are sometimes spared presbyopia because they focus too close to start with and do not depend on accommodation for near vision.

ACE (angiotensin converting enzyme):  The angiotensins are peptides (substances smaller than proteins) that act as vasoconstricting agents (causing blood vessels to narrow). Narrowing the diameter of the blood vessels sends up the blood pressure. ACE converts angiotensin to its activated form (called angiotensin II) enabling it to function. The ACE inhibitors are drugs that inhibit the formation of angiotensin II and are used for blood pressure control and congestive heart failure.

Acellular:  Not made up of cells or divided into cells. Or lacking intact cells as, for example, an acellular vaccine which may contain cellular material but not complete cells.

Acentric chromosome:  A fragment of a chromosome (one of the microscopically visible carriers of the genetic material DNA) that is lacking a centromere (the ”waist“ of the chromosome essential for the division and the retention of the chromosome in the cell) and so is lost when the cell divides.

Aceruloplasminemia:  A genetic disorder in which there is absence of the protein ceruloplasmin from blood and accumulation of iron in the pancreas, liver and brain, causing diabetes and progressive neurodegeneration with the tremors and gait abnormalities characteristic of Parkinson disease. Ceruloplasmin normally removes iron from cells. The absence of ceruloplasmin leads to the abnormal deposition of iron in cells, including those of the pancreas, liver, retina and the basal ganglia region of the brain. The iron deposition damages these tissues and leads to the clinical features of the disease which usually appear between 30 and 50 years of age. Aggressive treatment with desferoxamine, a chelating agent that takes up iron, may halt the progression of these complications. Aceruloplasminemia is caused by mutations in the gene encoding ceruloplasmin.

Acetabulum:  the cup-shaped socket of the hip joint. The head (upper end) of the femur (the thighbone) fits into the acetabulum and articulates with it, forming a ball-and-socket joint. The word ”acetabulum“ in Latin means "cup."

Acetaminophen:  A non-aspirin analgesic

Acetone:  In the body, a chemical that is formed when the body uses fat instead of glucose (sugar) for energy. The formation of acetone means that cells lack insulin or cannot effectively use available insulin to burn glucose for energy. Acetone passes through the body into the urine as one of the so-called "ketone bodies."

Acetylsalicylic acid (aspirin or ASA):  Aspirin is a good example of a tradename that has entered into the language. Aspirin was once the Bayer trademark for acetylsalicylic acid.

Achalasia:  A rare disease of the esophagus (swallowing tube), usually diagnosed in adults. Abnormal function of nerves and muscles of the esophagus causes difficulty swallowing and sometimes chest pain. Regurgitation of undigested food can occur, also coughing or breathing problems related to entry of food into the lungs. The problem is weakness of the lower portion of the esophagus and failure of the lower esophageal sphincter to open.

Achilles tendonitis:  Inflammation in the tendon of the calf muscle where it attaches to the heel bone. Achilles tendonitis causes pain at the back of the leg near the heel.

Achillodynia:  Pain due to inflammation of the Achilles tendon or the bursa associated with it.

Achlorhydria:  A lack of hydrochloric acid in the digestive juices of the stomach. It can be due to many diverse causes including: pernicious anemia (an autoimmune gastritis), other autoimmune conditions - such as autoimmune thyroid disease (Hashimoto's thyroiditis) and any cause of severe chronic gastritis. Heliobacter pylori is the most common agent that may lead to destruction of parietal cells, the cells that make hydrochloric acid in the stomach, and thus lead to achlorhydria.

Achondroplasia:  The most common form of short stature with disproportionately short limbs, commonly called dwarfism. It is is caused by mutation in the fibroblast growth factor receptor-3 gene (FGFR3), which is located on chromosome 4 in chromosome band 4p16.3.

Achoo syndrome:  A disorder characterized by nearly uncontrollable sneezing provoked in a reflex fashion by the sudden exposure of a dark-adapted subject to intensely bright light, usually to brilliant sunlight. The number of sneezes is usually 2 or 3, but can be up to about 40. Often called the photic sneeze reflex or the helio-ophthalmic outburst syndrome.

Achromatopsia:  (color blindness) An hereditary disorder of sight due to a lack of cones - cells in the retina which detect color.

Acid phosphatase:  Acid phosphatase is an enzyme that works under acid conditions and is made in the liver, spleen, bone marrow and the prostate gland. High serum levels of the enzyme may indicate prostate or bone disease.

Acid reflux disease:  A condition in which acid in the stomach comes up into the esophagus. This can occur because the valve separating the contents of the stomach from the esophagus does not function properly. This is usually a function of diet, especially the persistent consumption of greasy foods.

Acid-base balance:  Acid-base balance refers to the mechanisms the body strives to keep its fluids close to neutral pH while keeping the blood slightly aklaline. Blood must be alkaline at a pH of between 7.25 and 7.65 (7.0 is neutral), even if it means making the rest of the body acid.

Acidosis:  Too much acid in the blood and body, a distinctly abnormal condition that is the result of the accumulation of acid or the depletion of alkaline reserves. One prominent example is diabetic ketoacidosis. Acidosis also occurs in lung disease, and severe kidney disease. In the extreme form acidosis is a prelude to death. Milder forms are seen with poor diet, smoking, extreme exercise, no exercise, etc. Also, unrecognized chronic infections produce acid and result in a condition of chronic subclinical acidosis which probably ages the body prematurely. Common causes are dental infections and gut wall inflammatory conditions. The opposite of acidosis is alkalosis in which there is too high a pH due to excess base or insufficient acid in the body.

Acinus, pulmonary:  The ending of a tiny airway in the lung, where the alveoli (air sacs) are located. An acinus is a round cluster of cells that looks somewhat like a knobby berry. The word "acinus" means "berry" in Latin and the plural is "acini". There are also acini, round clusters of epithelial cells, in the salivary glands and in the pancreas.

ACL:  The anterior cruciate ligament, one of the ligaments in the knee.

Acne rosacea:  This term is actually a misnomer! The appropriate term is simply rosacea which is a chronic skin disease that affects the middle third of the face with persistent redness over the areas of the face and nose that normally blush: mainly the forehead, the chin and the lower half of the nose. The tiny blood vessels in these areas enlarge (dilate) and become more visible through the skin, appearing like tiny red lines (called telangiectasias).

Acne vulgaris:  The common form of acne seen most often in teenagers or young adults, acne vulgaris is the result of overactive oil glands that become plugged, red, and inflamed.

Acoustic nerve:  the 8th cranial nerve which is concerned with hearing and the sense of balance and head position. An acoustic neuroma is a tumor on the acoustic nerve.

Acrocephalosyndactyly:  An inherited disorder causing abnormalities of the skull and face and the hands and feet. There is closure too-early of some of the sutures of the skull (craniosynostosis). This results in an abnormally shaped head, which is unusually tall and peaked, and an abnormally shaped face with shallow eye sockets and underdevelopment of the midface. There is fusion of fingers and toes (syndactyly) and broad ends of the thumbs and big toes. It is an autosomal dominant trait with boys and girls affected equally. A affected parent can have transmit the gene for the disorder or both parents can be normal with the disorder appearing in the child due to a new mutation.

Acrochordon (cutaneous papilloma or skin tag):  A small tag of skin that may have a stalk (a peduncle). An acrochordon may appear on skin anywhere although the favorite locales are the eyelids, neck, armpits (axillae), upper chest, and groin. Invariably benign, this tiny tumor of the skin usually causes no symptoms unless repeatedly irritated as, for example, by the collar. Treatment may be done by freezing with liquid nitrogen or by cutting off with a scalpel or scissors if the acrochordon is irritating or cosmetically unwanted. (acro = peak; chordon = string)

Acrocyanosis:  Blueness of the hands and feet, typically symmetrical and marked by a mottled blue or red discoloration of the skin of the fingers and wrists and the toes and ankles and by profuse sweating and coldness of the fingers and toes. It is caused by constriction of small arteries toward the end of the arms and legs.

Acrodynia:  Pain in the hands and feet. (dynia = pain)

Acromegaly:  Condition due to the production of too much growth hormone by the pituitary gland after the end of adolescence. Manifests as thickening of the skin, soft tissues, and bones of the hands and feet. These effects are insidious and slowly progressive. Ultimately they cause considerable disability (aside from the need for larger rings, gloves, and shoes) including hoarseness, sleep apnea, joint pain, cardiovascular disease, hypertension, insulin resistance, visual impairment and severe headaches. Excessive growth hormone secretion may be caused by a tumor of the pituitary or may occur in the absence of tumor. Treatment is usually possible via medication or surgery. Inadequate treatment of acromegaly is associated with increases in deaths from cardiovascular causes, cancer, and other causes. One famous person with acromegaly (and mild gigantism which is the preadult manifestation of excess growth homrone) is Tony Robbins (the motivation guru, not the actor). Click here for an image: Tony Robbins

Acrophobia:  An abnormally excessive and persistent fear of heights. Sufferers experience severe anxiety even though they usually realize that, as a rule, heights pose no real threat to them.

Actinic:  Referring to the ultraviolet (UV) rays from sunlight and UV lamps. Sunburn is an actinic burn.

Actinic keratosis:  A small rough spot on skin chronically exposed to the sun, precancerous, can develop into a skin cancer called squamous cell carcinoma, a process that typically takes years. Actinic keratoses occur most frequently in fair-skinned people. Common locations are the face, scalp, back of the neck, upper chest, forearm and back of the hand.

Active immunity:  The production of antibodies against a specific agent by the immune system. Active immunity can be acquired in two ways: by contracting an infectious disease such as chickenpox or by receiving a vaccination such as that against chickenpox. Active immunity is usually permanent. The individual is protected from the disease all his or her life.

Acupressure:  The application of pressure on specific points on the body to control symptoms such as pain or nausea. Similar in concept to acupuncture but without needles.

Acupuncture:  The practice of inserting needles into the body to reduce pain or induce anesthesia. More broadly, acupuncture is a family of procedures involving the stimulation of anatomical locations on or in the skin by a variety of techniques

Acute:  Of short duration, rapid and abbreviated in onset, in reference to a disease. ”Acute“ is a measure of the time scale of a disease and is in contrast to ”subacute“ and ”chronic.“ ”Subacute“ indicates longer duration or less rapid change. ”Chronic“ indicates indefinite duration or virtually no change.

acute abdomen:  Clinical syndrome characterized by abdominal pain of great severity associated with other symptoms and signs, usually those of acute peritonitis, which is often the result of a ruptured abdominal viscus or other abdominal catastrophe requiring urgent surgical operation.

Acute abdomen:  The abrupt (acute) onset of abdominal pain. A potential medical emergency, an acute abdomen may reflect a major problem with one of the organs in the abdomen.

Acute angle-closure glaucoma:  Increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) blockage of the normal circulation of fluid within the eye.

Acute coronary syndromes:  A spectrum of conditions involving chest discomfort or other symptoms caused by lack of oxygen to the heart muscle (the myocardium).

Acute epiglottitis:  A very rapidly progressive infection causing inflammation of the epiglottis (the flap that covers the trachea) and tissues around the epiglottis that may lead to abrupt blockage of the upper airway and death. The inflamed epiglottis mechanically obstructs the airway; the work of breathing increases, and the retention of carbon dioxide and hypoxia (low oxygen) may result. Clearance of secretions is also impaired. These factors may result in fatal asphyxia within a few hours.

Acute fatty liver of pregnancy:  Liver failure in late pregnancy, usually from unknown cause, typically occurring in first-time pregnancies in the last trimester. If untreated, AFLP can cause complete liver failure, bleeding (because of impaired blood clotting) and death of the mother and child.

Acute HIV infection:  The body's initial reaction to infection by the HIV virus. Acute HIV infection is a flu-like syndrome that occurs immediately after a person contracts HIV (the human immunodeficiency virus 1, the agent that causes AIDS). The syndrome is characterized by fever, sore throat, headache, skin rash and swollen glands. This syndrome precedes seroconversion - the development of detectable antibodies to HIV in the blood as a result of the infection. It normally takes several weeks to several months for antibodies to the virus to develop after HIV transmission. When antibodies to HIV appear in the blood, a person will test positive in the standard ELISA test for HIV.

Acute idiopathic polyneuritis:  Also known as the Guillain-Barre syndrome, a disorder characterized by progressive symmetrical paralysis and loss of reflexes, usually beginning in the leg, with in most cases nearly complete or complete recovery. It is not associated with fever. There is paralysis involving more than one limb, most commonly the legs, and that paralysis is progressive. There is loss or diminution of reflexes, It is due to an immune response that results in the direct destruction of the myelin sheath surrounding the peripheral nerves or the axon of the nerve itself. The syndrome sometimes follow triggering events, including vaccinations. Among the vaccines reportedly associated are the swine influenza vaccine (in 1976-1977), the oral poliovirus vaccine, and tetanus toxoid. Aside from vaccinations, infection with the bacteria Campylobacter jejuni and viral infections can trigger the Guillain-Barre syndrome.

Acute leukemia:  Cancer of the white blood cells (leukemia) that characteristically comes on abruptly and (if not treated) progresses rapidly.

Acute lymphoblastic leukemia:  A form of leukemia that has a sudden onset and is characterized by the presence in the blood and bone marrow of large numbers of unusually immature white blood cells destined to become lymphocytes. These cells, called lymphoblasts, are rarely seen in the blood under normal circumstances. Treatment may include chemotherapy, radiation, biological therapy and bone-marrow transplantation. There is a high cure rate today, especially among children. Also called acute lymphocytic leukemia.

Acute membranous gingivitis:  This is trench mouth, a progressive painful infection with ulceration, swelling and sloughing off of dead tissue from the mouth and throat due to the spread of infection from the gums. Certain germs (including fusiform bacteria and spirochetes) have been thought to be involved, but the full story behind this long- known disease is still not clear.

Acute mountain sickness:  Acute mountain sickness is the effect on the body of being in a high altitude environment. It is common at high altitudes, that is above 8,000 feet (2,440 meters). Three-quarters of people have mild symptoms over 10,000 feet (3,048 meters). The occurrence depends on the altitude, the rate of ascent, and individual susceptibility. Many people experience mild AMS during the acclimatization process (the first 1 to 3 days at a given altitude). Symptoms usually start 12-24 hours after arrival at altitude and include headache, dizziness, fatigue, shortness of breath, loss of appetite, nausea, disturbed sleep, and a general feeling of malaise. These symptoms tend to be worse at night when respiratory drive is decreased.

Acute myelogenous leukemia:  Abbreviated AML. Also called acute myeloid leukemia or acute nonlymphocytic leukemia (ANLL). A quickly progressive malignant disease in which there are too many immature blood-forming cells in the blood and bone marrow.

Acute myeloid leukemia:  A quickly progressive malignant disease in which there are too many immature blood-forming cells in the blood and bone marrow, the cells being specifically those destined to give rise to the granulocytes or monocytes, both types of white blood cells that fight infections.

Acute myocardial infarction:  An acute myocardial infarction is a heart attack. The term "myocardial infarction" focuses on the heart muscle and the changes that occur in it due to sudden deprivation of oxygen. The main change is death of heart muscle cells. The usual cause is a combination of plaque formation and ”blood slugging.“

Acute otitis media:  inflammation of the middle ear. It typically causes fluid in the middle ear accompanied by a bulging eardrum and usually pain; or a perforated eardrum, often with drainage of pus.

Acute pancreatitis:  Sudden inflammation of the pancreas (the organ - actually two organs in one anatomical structure - which makes digestive enzymes and insulin). Some people have more than one attack but recover fully after each one. The cause of acute pancreatitis is most often alcohol abuse. Other causes include use of prescribed drugs, trauma or surgery to the abdomen. In rare cases, the disease may result from infections, such as mumps. In some cases the cause is unknown.

Acute promyelocytic leukemia (APL):  A malignancy of the bone marrow in which there is a deficiency of mature blood cells in the myeloid line and an excess of immature cells called promyelocytes. APL is due to a translocation (an exchange of chromosome material) between chromosomes 15 and 17. This translocation is the cause of APL.

Acute respiratory distress syndrome (ARDS):  Respiratory failure of sudden onset due to fluid in the lungs following an abrupt increase in the permeabi

Acute thrombocytopenic purpura (ATP):  Sudden onset of low blood platelet levels with bleeding into the skin and elsewhere. ATP is due to many causes. It may, for example, constitute a potentially serious complication during the acute phase of measles.

Acute-phase proteins:  Proteins whose plasma concentrations increase (or decrease) by 25% or more during certain inflammatory disorders. The best known of acute-phase proteins is C-reactive protein (CRP), a plasma protein that rises in the blood with the inflammation from certain conditions. The level of CRP in blood plasma can rise as high as 1000-fold with inflammation. Conditions that commonly lead to marked changes in CRP include infection, trauma, surgery, burns, inflammatory conditions, and advanced cancer. Moderate changes occur after strenuous exercise, heatstroke, and childbirth. Small changes occur after psychological stress and in several psychiatric illnesses.

Ad lib:  Abbreviation for the Latin "ad libitum" meaning "at pleasure" and "at one's pleasure, as much as one desires, to the full extent of one's wishes." Used in medicine to indicate that the patient may choose his own intake of food or drink, ordinarily applied as a doctor’s order in the hospital setting.

ADA deficiency:  Lack of normal adenosine deaminase (ADA) activity, a genetic (inherited) condition causing one form of severe combined immunodeficiency (SCID) disease.

Adam's apple:  A familiar anatomic feature in the front of the neck that is due to the forward protrusion of the thyroid cartilage, the largest and most prominent cartilage of the larynx.

Adams-Stokes disease:  Sudden collapse into unconsciousness due to a disorder of heart rhythm in which there is a slow or absent pulse resulting in fainting with or without convulsions. In this condition, the normal electrical flow passing from the upper chambers of the heart to the lower chambers is interrupted. This results in a condition called a "heart block." When a heart block occurs, the heart rate usually slows considerably. This can cause inadequate blood flow to the brain and result in fainting. This condition goes by a baffling number of names including the Adams-Stokes, Morgagni, Morgagni-Adams-Stokes, Spens syndrome, and Stokes-Adams disease or syndrome.

ADD (Attention Deficit Disorder):  An inability to control behavior due to difficulty in processing neural stimuli, usually manifesting in children. While in our drug oriented society Ritalin and other drugs are used to cope with this problem, the best results are obtained when these children are taken off refined sugar.

Addison’s anemia:  A blood disorder caused by a lack of vitamin B12. Patients who have this disorder do not produce the substance in the stomach that allows the body to absorb vitamin B12. This substance is called intrinsic factor (IF). Addison’s anemia, better known today as pernicious anemia (PA), is characterized by the presence in the blood of large, immature, nucleated cells (megaloblasts) which are forerunners of red blood cells. (Red blood cells, when mature, have no nucleus). It is thus a type of megaloblastic anemia. Pernicious anemia (PA) was first described (although not by that name) in 1855 by the English physician Thomas Addison. He called it an invariably fatal ”idiopathic anemia.“ Dr. Addison also described the adrenal collapse now known as Addison’s disease.

Addison’s disease:  Long-term underfunction of the outer portion of the adrenal gland, i.e. chronic insufficiency of the adrenal cortex. This may be due to physical trauma, hemorrhage, tuberculosis of the adrenal, and destruction of the cells in the pituitary gland that secrete ACTH (adrenocorticotropic hormone) which normally drives the adrenal. Addison’s disease is characterized by bronzing of the skin, anemia, weakness, and low blood pressure. President John. F. Kennedy is said to have had Addison disease. When Addison first identified adrenal insufficiency in 1849, tuberculosis (TB) was responsible for 70-90% of cases. As the treatment for TB improved, the incidence of adrenal insufficiency due to TB of the adrenal glands greatly decreased. TB now accounts for around 20% of cases of primary adrenal insufficiency in developed countries.

Adduction:  Movement of a limb toward the midline of the body. The opposite of adduction is abduction. An adductor muscle pulls toward the midline of the body. For example, the adductor muscles of the legs pull the legs toward the midline of the body so the legs are closer together.

Adenine:  One member of the A-T (adenine-thymine) base pair in DNA. The other base pair in DNA is G-C (guanine-cytosine).

Adenocarcinoma:  A cancer that develops in the lining or inner surface of an organ. More than 95 percent of prostate cancers are adenocarcinoma.

Adenoidectomy:  The surgical removal of the adenoids.

Adenoids:  Masses of lymphoid tissue in the upper part of throat behind the nose.

Adenoma:  A benign tumor that arises in or resembles glandular tissue. If it becomes cancerous, it is called an adenocarcinoma.

Adenomyoma:  A nodule that forms around tissue of the inner uterus (endometrial tissue) as a result of adenomyosis.

Adenosine deaminase (ADA) deficiency:  An inherited condition that results in a immune deficiency disorder called severe combined immunodeficiency disease (SCIDS). Adenosine deaminase is an enzyme that plays a key role in restoring purine molecules. The first successful instance of gene therapy in humans was carried out in 1990 by Drs. W. French Anderson, R. Michael Blaese and Kenneth W. Culver who infused genetically engineered blood cells to repair ADA deficiency.

Adenosine thallium scan:  An examination of the heart to obtain information about its blood supply. Cameras take a series of pictures of the heart, then radioactive thallium is injected into the bloodstream as a tracer. The tracer attaches to certain cells and makes them visible to the camera. The tracer attaches to the muscle cells of the heart so the imaging camera can take pictures of the heart muscles. If an area of the heart does not receive an adequate flow of blood, the cells in the under-served area do not receive as much tracer and it appears as a darker area on the picture. In lieu of exercise on a treadmill, the medication adenosine is given IV to exercise the heart.

Adenosine Triphosphate (ATP):  A compound of critical importance in the storage of energy within cells in the body and in the synthesis (the making) of RNA. ATP is a nucleotide (a building block of a nucleic acid such as RNA). The body produces ATP from food. ATP stores energy which is released as the phosphates are liberated from the adenosine portion of the molecule.

Adenovirus:  A group of viruses responsible for a spectrum of respiratory disease as well as infection of the stomach and intestine, eyes, and bladder, as well as skin rash. Adenovirus respiratory diseases include a form of the common cold, pneumonia, croup, and bronchitis.

ADH (antidiuretic hormone):  A peptide molecule that is released by the pituitary gland at the base of the brain after being made nearby (in the hypothalamus). ADH has an antidiuretic action that prevents the production of dilute urine (and so is antidiuretic). A syndrome of inappropriate secretion of ADH may occur in association with oat-cell lung cancer, pancreatic cancer, prostate cancer, and Hodgkin's disease as well as a number of other disorders. ADH is also known as vasopressin.

Adhesion:  The union of two opposing tissue surfaces (often in reference to the sides of a wound). Also refers to scar tissue strands that can form in the area of a previous operation, such as within the abdomen after a laparotomy.

Adhesive capsulitis:  Constant severe limitation of the range of motion of the shoulder due to scarring around the shoulder joint. Also called a "frozen shoulder."

Adipocyte:  A fat cell, a connective tissue cell that has differentiated and become specialized in the synthesis (manufacture) and storage of fat. The adipocyte is important to the body in maintaining proper energy balance, storing calories in the form of lipids, mobilizing energy sources in response to hormonal stimulation, and commanding changes by signal secretions.

Adiponectin:  A hormone secreted by fat cells (adipocytes) that affects the body's response to insulin and may have other important effects.

Adipose:  means "fat" but is usually used to refer specifically to tissue made up of mainly fat cells such as the yellow layer of fat beneath the skin.

Adjuvant:  a method or approach which supplements another treatment. For example, adjuvant therapy for cancer after surgery can be chemotherapy or radiation. In the pharmaceutical realm an adjuvant is a substance that enhances the pharmacological effect of a drug.

Adnexa:  This Latin word (in the plural) is used in medicine in reference to appendages. For example, in gynecology the adnexa are the "appendages" of the uterus, namely the ovaries, Fallopian tubes and ligaments that hold the uterus in place.

Adrenal cortex:  The outer portion of the adrenal gland located on top of each kidney. The adrenal cortex produces steroid hormones which regulate carbohydrate and fat metabolism and mineralocorticoid hormones which regulate salt and water balance in the body. Under-function of the adrenal cortex results in Addison disease while over-function occurs in the adrenogenital syndrome and in Cushing syndrome.

Adrenal failure:  A condition in which the adrenal glands do not produce enough of the adrenal hormones that control important functions such as blood pressure.

Adrenal glands:  The adrenal glands are a pair of small glands, each of which sits on top of one of the kidneys. The adrenal is made up of an outer wall (the cortex) and an inner portion (the medulla). The adrenal glands produce hormones that help control the heart rate, blood pressure, the way the body uses food, and other vital functions. The adrenal cortex secretes steroid (cortisone-related) hormones and mineralocorticoids that regulate the levels of minerals such as sodium and potassium in the blood. The adrenal medulla makes adrenaline (epinephrine) noradrenaline (norepinephrine). Adrenaline is secreted in response to low blood levels of glucose as well as exercise and stress; it causes the breakdown of the storage product glycogen to the sugar glucose in the liver, facilitates the release of fatty acids from adipose (fat) tissue, causes dilation (widening) of the small arteries within muscle and increases the output of the heart. Noradrenaline is a neurotransmitter for the sympathetic nervous system.

Adrenal medulla:  The inner portion of adrenal gland. (The outer portion is the adrenal cortex).

Adrenaline:  A substance produced by the adrenal medulla (inside) of the adrenal gland. It is synonymous with epinephrine. Adrenaline is a sympathomimetic catecholamine, i.e. it causes quickening of the heart beat, strengthens the force of the heart contraction, opens up the bronchioles in the lungs and has numerous other effects. The secretion of adrenaline by the adrenal is part of the "fight-or-flight" reaction that we have in response to being frightened.

Adrenoleukodystrophy:  A rare genetic disorder characterized by the breakdown or loss of the myelin sheath surrounding nerve cells in the brain and progressive dysfunction of the adrenal gland. Adrenoleukodystrophy (ALD) is one of a group of genetic disorders called the leukodystrophies that cause damage to the myelin sheath of the nerve fibers in the brain. The myelin sheath is a fatty covering which acts as an electrical insulator.

Adult primary liver cancer:  A tumor in which the cancer starts during adulthood in cells in the liver. Also called hepatocellular carcinoma. Primary liver cancer is different from cancer that has metastasized (spread) from another place in the body to the liver. Hepatitis B and C appear to be the most significant causes worldwide. People who have both hepatitis B and hepatitis C may be at even higher risk if they consume more than 3 oz. (80 grams) of alcohol a day. A history of a first-degree relative with hepatocellular carcinoma also increases the risk.

Adult respiratory distress syndrome:  Respiratory failure of sudden onset due to fluid in the lungs (pulmonary edema) following an abrupt increase in the permeability of the normal barrier between the capillaries in the lungs and the air sacs. Also known as acute respiratory distress syndrome (ARDS), ARDS is the most serious response to acute lung injury. Causes include but are not limited to aspiration, inhalation of a toxic substance, widespread infection of the lungs, sepsis and near-drowning.

Adult-onset diabetes:  Non-insulin-dependent or type II diabetes, the most common form of diabetes mellitus; about 95 percent of people who have diabetes have this type. Unlike the insulin-dependent type of diabetes in which the pancreas makes insufficient insulin, people with adult-onset diabetes produce some insulin, usually excess amounts, however their cells are resistant to the action of insulin. Generally, this kind of diabetes occurs in people who are over age 40. It is strongly associated with being overweight and having indulged in a diet heavy in simple and/or refined carbs for many years. It is best treated in almost every case with certain nutritional supplements, proper diet, exercise, and weight loss. Intravenous EDTA chelation therapy has a remarkably positive effect in most cases. Most people are able to recover from this condition through these means.

Adult-onset Still disease:  Although Still disease was first described in children, it is known to begin in adults, but rarely. 100% have high intermittent fever; 100% have joint inflammation and pain, muscle pain with fevers, and develop persistent chronic arthritis. Ninety-five percent (95%) have the faint salmon-colored skin rash. Eighty-five percent (85%) have swelling of the lymph glands or enlargement of the spleen and liver; and 85% have a marked increase in the white blood cell count. Sixty percent (60%) have inflammation of the lungs (pleuritis) or the heart sack (pericarditis). Forty percent (40%) have severe anemia. And twenty percent (20%) have abdominal pain.

Advance medical directives:  These directives pertain to treatment preferences and the designation of a surrogate decision-maker in the event that a person should become unable to make medical decisions on his or her own behalf. Advance directives generally fall into three categories: living will, power of attorney and health care proxy.

Adventitia:  The outermost connective tissue covering of any organ, vessel, or other structure. For example, the connective tissue that surrounds an artery is called the adventitia because it is considered extraneous to the artery.

Adverse effect:  A harmful or abnormal result. An adverse effect may be caused by exposure to a drug or chemical. Examples of adverse effect are headache, nausea, drop in blood pressure and sudden death.

Aerobic:  Oxygen-requiring. Aerobic bacteria need oxygen to grow. Aerobic exercise requires the heart and lungs to work harder to meet the body's increased oxygen demand.

Aerobic exercise:  Brisk physical activity that requires the heart and lungs to work harder to meet the body's increased oxygen demand. Aerobic exercise promotes the circulation of oxygen through the blood. Examples of aerobic exercise include running, swimming and cycling.

Aerophagia:  The word "phage" in Greek means "to eat." Aerophagia is literally to eat air. Aerophagia is a common cause of gas in the stomach and an uncommon cause of flatulence. Everyone swallows small amounts of air when eating or drinking. However, rapid eating or drinking, chewing gum, smoking, or ill-fitting dentures may cause a significant increase in swallowed air.

Aerophobia:  An abnormal and persistent fear of flying. Sufferers experience severe anxiety even though they usually realize that the flying does not pose a threat commensurate with their fear. A second meaning is: an irrational fear of fresh air or drafts of air.

Aerosinusitis:  Sinus troubles, particularly with pain, due to changing atmospheric pressures, as when going up or down in a plane. Also called barosinusitis or sinus barotrauma.

Aerosol:  A fine mist or spray which contains minute particles.

Aerotitis:  Middle ear problems due to changing atmospheric pressures, as when a plane descends to land. The problems include ear pain, ringing, diminished hearing and, sometimes, dizziness.

Aesculapius:  The stick with the snake curled around it is the staff (the rod) of Aesculapius (also called Asklepios), the ancient god of medicine. His Greek name was Asklepios and his Roman name Aesculapius. Asklepios may have been a real person who was renowned for his gentle, humane remedies and his humane treatment of the mentally ill. His followers established temples called asclepions, temples of Asklepios, temples of healing. The greatest asklepion was in a grove of trees south of Corinth, Greece where the sick had to spend a night while the proper remedies were revealed during a dream to the priests of the temple and the cured had to make a suitable sacrifice.

Afferent:  Carrying toward. A vein is an afferent vessel since it carries blood toward from the heart. The opposite of afferent is efferent.

Afferent nerve:  A nerve that carries impulses toward the central nervous system (CNS). The opposite of an afferent nerve is an efferent nerve that carries impulses away from the CNS.

Afferent vessel:  A vessel that carries blood toward the heart. A vein or venule.

Aflatoxin:  A toxin produced by mold that is hepatotoxic (can damage the liver) and may possibly lead to liver cancer. Aflatoxins are known to cause cancer in animals. The fungi that produce aflatoxin grow on crops such as peanuts (especially) and wheat, corn, beans and rice. Aflatoxin is a problem particularly in undeveloped and developing countries. Aflatoxin is a naturally occurring mycotoxin produced by two types of mold: Aspergillus flavus and Aspergillus parasiticus. Aspergillus flavus is common and widespread in nature and is most often found when certain grains are grown under stressful conditions such as drought. The mold occurs in soil, decaying vegetation, hay, and grains undergoing microbiological deterioration and invades all types of organic substrates whenever and wherever the conditions are favorable for its growth. Favorable conditions include high moisture content and high temperature.

African tapeworm:  The beef tapeworm (Taenia saginata), the most common of the big tapeworms that parasitizes people, contracted from infected raw or rare beef. Can grow to be 12-25 feet (3.6-7.5 m) long in the human intestine.

African tick typhus:  One of the tick-borne rickettsial diseases of the eastern hemisphere, similar to Rocky Mountain spotted fever, but less severe, with fever, a small ulcer (tache noire) at the site of the tick bite, swollen glands nearby (satellite lymphadenopathy), and a red raised (maculopapular) rash.

Agammaglobulinemia:  Total or near-total absence of gamma globulin, a protein fraction of the blood rich in antibodies, due to certain genetic diseases such as Bruton agammaglobulinemia or to acquired diseases such as HIV/AIDS.

Age-related macular degeneration:  Age-related macular degeneration is a disease with its onset usually after age 60 that progressively destroys the macula, the central portion of the retina, impairing central vision. AME rarely causes blindness because only the center of vision is affected. However this can impair the ability to see straight ahead and makes it difficult to read, drive, or perform other daily activities that require fine central vision. The macula is in the center of the retina at the back of the eye. As one reads, light is focused onto the macula where millions of cells change the light into nerve signals that travel to the brain and tell it what we are seeing. This is "central vision."

Agenesis:  Lack of development of something. For example, agenesis of a toe means that toe failed to form.

Ageusia:  The inability to taste (the primary tastes are sweet, sour, bitter, and salt). Some people can taste but their ability to do so is reduced; they are said to have hypogeusia.

Aggressive angiomyxoma:  A slow-growing tumor which occurs primarily in the genital and pelvic regions. This tumor is much more common in women. It can range from relatively small tumors to football-size masses in the pelvis. Treatment consists of surgical excision. There is a relatively high rate of recurrence because the exact extent of the tumor is difficult for the surgeon to determine. These tumors appear not to have the ability to metastasize.

Agnosia:  An inability to recognize sensory inputs (sight, sound, touch). The most common agnosia is a result of brain injury damaging the rear part of the brain causing visual agnosia (inability to properly recognize what one is seeing). Tactile agnosia is the inability to recognize objects by touch alone.

Agonist:  A drug that binds to a receptor of a cell and triggers a response by the cell. An agonist often mimics the action of a naturally occurring substance. An agonist produces an action. It is the opposite of an antagonist which acts against and blocks an action. Agonists and antagonists are key agents in the chemistry of the human body and important players today in pharmacology. There are agonists now for many of the known hormones. For example, LHRH (luteinizing hormone-releasing hormone) agonists are similar to LHRH in structure and are able to mimic the effects of LHRH, a hormone that controls sex hormones in both men and women.

Agoraphobia:  An abnormal and persistent fear of public places or open areas, especially those from which escape would be difficult or help not immediately available. Persons with agoraphobia frequently also have panic disorder and characteristically become anxious if they even think about being trapped in a situation where it might be difficult to leave. People with agoraphobia also avoid the situations which bring them anxiety or panic. People with mild agoraphobia often live normal lives by avoiding anxiety-provoking situations. But, in the most severe cases, the victims may be incapacitated and be homebound. The disorder affects women twice as often as men, tends to start in the mid to late 20’s and the onset may appear triggered by a traumatic event. Agoraphobia comes from the Greek agora, marketplace + phobos, fear = fear of the marketplace.

Agranulocytosis:  A marked decrease in the number of granulocytes. Granulocytes are a type of white blood cell filled with microscopic granules that are little sacs containing enzymes that digest microorganisms. Granulocytes are part of the innate, somewhat non specific infection-fighting immune system. They do not respond exclusively to specific antigens, as do B-cells and T-cells. Agranulocytosis results in a syndrome of frequent chronic bacterial infections of the skin, lungs, throat, etc. Although "agranulocytosis" literally means no granulocytes, there may, in fact, be some granulocytes but too few of them, i.e. granulocytopenia. Agranulocytosis can be genetic and inherited or it can be acquired as, for example, an aspect of leukemia. Neutrophils, eosinophils and basophils are all types of granulocytes.

Agranulocytosis, infantile genetic:  Children born with this condition lack neutrophils (a type of white blood cell that is important in fighting infection). These children suffer frequent infections from bacteria which in the past led to death in three-quarters of cases before 3 years of age.

Ague:  A fever marked by paroxysms of chills, fever, and sweating recurring regular intervals. Also a fit of shivering, a chill. Hence, ague can refer to both chills and fevers.

Agyrophobia:  Abnormal and persistent fear of crossing streets, highways and other thoroughfares; fear of thoroughfares themselves. Sufferers experience anxiety even though they realize that streets, highways and other thoroughfares pose no threat commensurate with their fear. Formed from the Greek gyrus (turning or whirling) and the Greek phobos (fear). The first letter, "a," is privative--that is, it creates a negative. Thus, an agyrophobiac shuns or avoids the whirl of traffic.

AID (artificial insemination by donor):  A procedure in which a fine catheter (tube) is inserted through the cervix (the natural opening of the uterus) into the uterus (the womb) to deposit a sperm sample from a donor other than the woman's mate directly into the uterus. The purpose of this procedure is to achieve fertilization and pregnancy. AID is also called heterologous insemination. AID is distinguished from homologous insemination, that is artificial insemination by husband (AIH) (see below).

AIDS (Acquired Immunodeficiency Syndrome):  It is a multifactoral collapse of the immune system strongly associated with the human immunodeficiency virus (HIV) but requiring other debilitating factors to be present for clinical expression.

AIDS dementia complex:  The AIDS dementia complex is a brain disorder that occurs in people with AIDS that causes the loss of cognitive capacity, affecting the ability to function in a social or occupational setting. The exact mechanism by which it is triggered has not been determined.

AIDS-Related Complex:  In the early years of the AIDS epidemic, this term was used to describe people with HIV infection who had mild symptoms of illness, such as swollen lymph glands. It is rarely used today.

AIH (artificial insemination by husband):  A procedure in which a fine catheter (tube) is inserted through the cervix (the natural opening of the uterus) into the uterus (the womb) to deposit a sperm sample from the woman's mate directly into the uterus. The purpose of this procedure is to achieve fertilization and pregnancy. AIH is distinguished from artificial insemination by donor (AID) in which the donor is a man other than the woman's mate (see above). AIH is also known as homologous insemination.

Ailurophobia:  An abnormal and persistent fear of cats which produces an undue anxiety reaction even though sufferers realize their fear is irrational. Sufferers of ailurophobia may fear not only the scratch or bite of a cat, but also the "evil mystique" of cats.

Air-conditioner lung:  A form of the sick building syndrome caused by organisms that contaminate humidifiers and the piping of air conditioner ducts. The air conditioner blows cold air containing spores of the organisms throughout the building. The organisms responsible for air-conditioner lung are the same as cause farmer's lung which is due to repeated inhalation of dust from hay. (The organisms are thermophilic actinomycetes).

Airway:  The path air follows to get into and out of the lungs. The mouth and nose are the normal entry and exit ports. Entering air then passes through the back of the throat (pharynx), continues through the voice box (larynx), down the trachea, and finally out the branching tubes known as bronchi.

Airway obstruction:  Partial or complete blockage of the breathing tubes to the lungs. Obstruction of the airway can be due to different causes including foreign bodies, allergic reactions, infections, anatomical abnormalities and trauma

Akinesia:  Impaired body movement; without movement, or without much movement. Akinesia is a term used in neurology to denote the absence or poverty of movement.

Akinetic:  Without movement (or without much movement). A term used in neurology to denote the absence or poverty of movement.

Akinetic mutism:  A state in which a person is mute and unmoving akinetic. A person with akinetic mutism has sleep-waking cycles but, when apparently awake, with eyes open, lies mute, immobile and unresponsive. It is often due to damage to the frontal lobes of the brain.

Alanine:  An amino acid, one of the 20 amino acids that serve as the building blocks in protein. Alanine is not an "essential" amino acid. (It is not essential to the diet, but can be made by the body from other substances. Alanine was discovered in protein in 1875.

Alanine aminotransferase (ALT):  An enzyme that is normally present in liver and heart cells. ALT is released into blood when one or both of these organs are damaged. Blood ALT levels are thus elevated with liver damage (for example, from viral hepatitis) or with an insult to the heart (for example, from a heart attack). Some medications can also raise ALT levels. ALT is also called serum glutamic pyruvic transaminase (SGPT).

Albinism:  Partial or total lack of the pigment melanin in the skin, hair and iris. The term "albino" was first applied by the Portuguese to "white" people they encountered in West Africa. Those "white" people probably had partial or complete albinism, an inherited lack of pigment in the skin, hair, and eyes. The lack of pigment in the eye impairs vision and often leads to jerky involuntary rhythmic eye movements called nystagmus.

Albright syndrome:  A genetic disorder of bones, skin pigmentation and hormonal problems with premature sexual development. Also called McCune-Albright syndrome and polyostotic fibrous dysplasia.

Albuginea:  Tough white fibrous tissue. The tunica albuginea of the testis, for example, is the layer of dense whitish inelastic tissue that surrounds the testes.

Albumen:  The white of an egg.

Albumin:  The main protein in human blood and the key to the regulation of the osmotic pressure of blood. Chemically, albumin is soluble in water, precipitated by acid, and coagulated by heat.

Albuminuria:  More than the normal amount of albumin in the urine. Albumin is the main protein in human blood and it is the key to the regulation of the osmotic pressure of blood. Some albumin is normal in the urine. But too much albumin in the urine means that protein is leaking through the kidney, most often through the glomeruli. Albuminuria can mean many things. Thus, for example, albuminuria may be a sign of significant kidney disease or it may simply be a sequel of vigorous exercise. Albuminuria is a form of proteinuria.

Alcohol:  An organic chemical in which one or more hydroxyl (OH) groups are attached to carbon (C) atoms in place of hydrogen (H) atoms. Common alcohols include ethyl alcohol or ethanol (found in alcoholic beverages), methyl alcohol or methanol (can cause blindness) and propyl alcohol or propanol (used as a solvent and antiseptic). Rubbing alcohol is a mixture of acetone, methyl isobutyl ketone, and ethyl alcohol. In everyday talk, ”alcohol“ usually refers to ethanol as, for example, in wine, beer, and liquor. It can cause changes in behavior and be addictive. The word "alcohol" came from the Arabic "al" (the) = "kuhl" (a fine impalpable powder) and referred originally to finely powdered antimony which women used to tint their eyelids.

Aldose reductase inhibitor:  A class of drugs used to prevent eye and nerve damage in diabetes. Aldose reductase is an enzyme that is normally present in the eye and in many other parts of the body. It helps change glucose into a sugar alcohol called sorbitol. Too much sorbitol trapped in eye and nerve cells can damage these cells, leading to retinopathy (retinal disease) and neuropathy (nerve disease). Drugs that prevent or slow the action of aldose reductase may represent a means to prevent or delay these complications of diabetes.

Aldosterone:  A hormone made by the outer portion (cortex) of the adrenal gland that regulates the balance of salt and water in the body. It is secreted in response to low salt levels and activates the MR (for mineralocorticoid receptor) gene. The product of the MR gene stimulates the kidney to reabsorb and retain salt, thereby retaining water. (An MR gene mutation leads to salt retention and high blood pressure early in life which becomes much worse with pregnancy.)

Aldosteronism:  Overproduction of the hormone aldosterone from the cortex (the outer layer) of the adrenal gland or a tumor containing that type of tissue. Excess aldosterone results in low potassium levels (hypokalemia), underacidity of the body (alkalosis), muscle weakness, excess thirst (polydipsia), excess urination (polyuria), and high blood pressure (hypertension). Also called hyperaldosteronism or Conn’s syndrome.

Alembic:  A type of still, an apparatus used in the process of distillation. Alembics were employed in chemistry and biomedical laboratories as well as in distilling cognac. By extension, "alembic" is anything that refines or transmutes as if by distillation. For example, the alembic of the author's mind.

Alexia:  A loss of the reading ability or the ability to understand the written word due to brain damage that disconnects these functions. Alexia is a complex visual disturbance resulting from disease or damage in the visual-association areas at the back of the brain. (G. literally without word)

Algophobia:  An abnormal and persistent fear of pain which is excessive, beyond that which is expected under the circumstances, producing an anxiety reaction. (G. pain fear)

Alien hand syndrome:  The feeling that one's hand is possessed by a force outside of ones control. The syndrome typically arises after trauma to the brain, after brain surgery or after a stroke or an infection of the brain. A person with the alien hand syndrome can feel sensation in the affected hand but thinks that the hand is not part of his or her body and believes there is no personal control over its movement, that it belongs to an alien. There is no cure for alien hand. All a patient can do to control the problem is to keep the hand busy by having it hold an object.

Alkaline phosphatase:  An enzyme made in the liver, bone, and the placenta and normally present in high concentrations in growing bone and in bile. It is released into the blood during injury and during normal activities such as bone growth and pregnancy. It is measured in a routine blood test. Abnormally high blood levels of alkaline phosphatase may indicate disease in bone or liver, bile duct obstruction, or certain malignancies. The enzyme is often elevated in chronic myelogenous leukemia. Abnormally low levels of alkaline phosphatase is a genetic condition called hypophosphatasia which results in bone deformities.

Alkalosis:  A dangerous decrease in the normal acidity of the blood where there is too much base in the blood and body resulting from accumulation of base or the depletion of acid. The pH of the alkalotic body measures above normal. It can be caused by high altitudes, hyperventilation, and excessive vomiting. The opposite of alkalosis is acidosis in which there is too low a pH due to excess acid or insufficient base in the body.

ALL:  Acute lymphoblastic leukemia, also called acute lymphocytic leukemia, an acute rapidly progressive form of leukemia characterized by the presence in the blood and bone marrow of large numbers of unusually young (immature) white blood cells destined to become lymphocytes. These cells, called lymphoblasts, are rare items in the blood under normal circumstances.

Allele:  An alternative form of a gene. One of the different forms of a gene that can exist at a single locus (spot on a chromosome). Also one of the different forms of any segment of a chromosome.

Allergen:  A substance that is foreign to the body and can cause an allergic reaction in a susceptible person. Examples are pollen, house dust, cat danders, and perfumes.

Allergic conjunctivitis:  Inflammation of the whites of the eyes (the conjunctivae) with itching and redness of the eyes and tearing, due to allergy.

Allergic contact dermatitis:  A red, itchy, weeping reaction where the skin has come into contact with an allergen; for example poison ivy, poison oak or poison sumac or certain preservatives in creams and lotions. This type of reaction reflects a specific sensitivity or allergy to a specific substance. Also called allergic contact eczema.

Allergic granulomatosis (or allergic granulomatous angiitis):  A disease (also often called the Churg-Straus syndrome) characterized by inflammation of the blood vessels in persons with a history of asthma or allergy.

Allergic rhinitis:  Medical term for ”hay fever,“ a condition due to allergy that mimics a chronic cold. ”Hay fever“ is a misnomer since hay is not a usual cause of this problem and there is no fever. Many substances can cause the allergic symptoms in hay fever, most commonly pollen and most commonly in the Springtime. (Rhinitis means "irritation of the nose" and is derivatived from Rhino, referring to the nose). Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing eyes. Post-nasal dripping of clear mucus frequently provokes coughing. Eye itching, redness, and tearing frequently accompany the nasal symptoms. If this condition persists throughout the year it is termed perennial allergic rhinitis. If not it is called seasonal allergic rhinitis.

Allergy:  A mistaken reaction to foreign substances by the immune system. Mistaken in that these foreign substances are usually harmless. The substances that trigger allergy are called allergens. Examples include pollens, dust mite, molds, danders, and certain foods. People with allergies are said to be allergic or atopic. Allergens cause the over-production of immunoglobulin E (IgE), an antibody we all have in small amounts which is designed to protect us from parasites. During the sensitization period in allergy, IgE is overproduced. It coats mast cells which contain histamine. Histamine causes inflammation and the typical allergic symptoms when released in the presence of allergens.

Allergy desensitization (or allergy immunotherapy):  Stimulation of the immune system with gradually increasing doses of the substances to which a person is allergic, in order to reduce the strength of the IgE and its effect on the mast cells; very effective for allergies to pollen, mites, cats, and especially stinging insects. Usually takes 6 months to a year to become effective and injections are usually required for 3-5 years.

Allergy scratch test:  Test done on the skin to identify the allergen that triggers an allergic reaction.

Allergy to cockroaches:  A condition that manifests as an allergic reaction when one is exposed to tiny particles from cockroaches. Asthma can be due to exposure to cockroach allergens (allergy-provoking substances). These substances are the proteins shed or excreted by the cockroaches.

Allergy to cow’s milk:  Casein and whey are the two major proteins of human milk and most milk-based formulas. Some (less than 8% of) infants have a true allergy to the cow proteins that are in milk-based formulas.

Alloerotic:  Having to do with sexual excitement toward the same sex. The opposite is heteroerotic.

Allopathy:  The system of medical practice which treats disease by the use of remedies which produce effects different from those produced by the disease under treatment. ”Mainstream medicine“ is allopathic in nature. The term "allopathy" was coined in 1842 by C.F.S. Hahnemann to designate the usual practice of medicine as opposed to homeopathy, the system of therapy he founded based on the concept that disease can be treated with drugs (in minute doses) thought capable of producing the same symptoms in healthy people as the disease itself.

Alopecia:  Baldness. There are many types of alopecia, each with a different cause. Alopecia may be localized to the front and top of the head as in common male pattern baldness. It may be patchy as in a condition called alopecia areata. Or it can involve the entire head as in alopecia capitis totalis. The word "alopecia" comes from the Greek "alopex" for "fox." Foxes are less furry when afflicted with a skin disease (the "mange") which causes them to lose their hair.

Alopecia areata:  Patchy baldness (alopecia means baldness and areata means occurring in patches) which typically begins on the scalp and sometimes progresses to complete baldness and even loss of body hair. The hair loss tends to be rather rapid and asymmetrical. It affects both males and females. It tends to occur most often in children and young adults. The most common pattern of alopecia areata is one or more spots of hair loss on the scalp. There is also a form of more generalized thinning. The cause appears to involve an autoimmune mechanism. Biopsies of affected skin show lymphocytes inside of hair follicles where lymphocytes normally are not present. The cause is unknown.

Alopecia capitis totalis:  Loss of all of the scalp hair with normal hair elsewhere on the body.

Alopecia traumatica:  Loss of hair caused by grooming methods that attempt to straighten the natural kinkiness of hair in order to make the hair more manageable. It is a result of stress traction injury from tight rollers and braiding as well as overheating the hair shafts. Vigorous combing and chemical bleaches and styling products can additionally irritate the scalp to cause further hair loss.

Alopecia universalis:  Absence of all of the hair, not only on the scalp, but also on the entire body. Affected individuals are born without eyebrows and eyelashes and never develop axillary or pubic hair. They have hair follicles which are devoid of hair. The disorder is inherited as an autosomal recessive trait. It is caused by a mutation in a gene dubbed HR in chromosome band 8p21.2 that is the human homolog of the mouse "hairless" gene - the human version of the gene in the mouse that is responsible for hairless mice.

Alpha cell, pancreatic:  A type of cell in the pancreas. Within the pancreas, the alpha cells are located in areas called the islets of Langerhans. Alpha cells make and release glucagon which raises the level of glucose (sugar) in the blood. Alongside are the beta cells which make insulin.

Alpha Fetoprotein (AFP):  Alpha Fetoprotein (AFP): A plasma protein normally produced by the fetus. It serves as the basis for tests. AFP is manufactured mainly in the fetus's liver and, also, in the fetal gastrointestinal tract and the yolk sac, a structure temporarily present during embryonic development. The level of AFP is typically high in fetal blood. It goes down in the baby's blood after birth. And by a year of age, it is virtually undetectable. During pregnancy, AFP crosses the placenta from the fetal circulation and appears in the mother's blood. The level of AFP in the mother's blood (the maternal serum AFP) provides a screening test for a number of disorders including:

• Open neural tube defects (anencephaly and spina bifida)
• Down syndrome (and other chromosome abnormalities)

The maternal serum AFP (MSAFP) tends to be:

• High with open neural tube defects such as anencephaly and spina bifida (meningomyelocele)
• Low with Down syndrome (trisomy 21, an extra chromosome number 21).

AFP production is essentially nil after a year of age. However, it starts up again under the stimulus of some diseases in the liver. It may be produced by the liver in viral hepatitis and cirrhosis of the liver. AFP is also made by primary liver tumors (hepatomas) and by germ cell tumors (teratocarcinoma and embryonal cell carcinomas). A person's serum AFP level can therefore be used to help detect these conditions and monitor their treatment.

Alpha interferon:  The interferons are specialized proteins (lymphokines) produced by the body in response to an infection. these substances interfere with cell infection. There are 3 main classes of interferon, alpha, beta, and gamma.

Alpha thalassemia:  A blood disorder, thalassemia is not one disease but rather a group of disorders that have a single feature in common: they all have a genetic defect in the production of hemoglobin, and thus produce a form of anemia. The problem in the thalassemias is with globin production. The thalassemias are classified according to the type of globin polypeptide chain that is underproduced. The alpha chain is involved in alpha thalassemia (and the beta chain is affected in the more familiar beta thalassemia).

Alpha-Fetoprotein (AFP):  AFP is a plasma protein that is normally produced by the fetus. It serves as the basis for some valuable tests. AFP is manufactured principally in the fetus's liver and, also, in the fetal gastrointestinal tract and the yolk sac, a structure temporarily present during embryonic development. The level of AFP is typically high in the fetus's blood. It goes down in the baby's blood after birth. And by a year of age, it is virtually undetectable. During pregnancy, AFP crosses the placenta from the fetal circulation and appears in the mother's blood. The level of AFP in the mother's blood (the maternal serum AFP) provides a screening test for a number of disorders including open neural tube defects (anencephaly and spina bifida); and Down syndrome and other chromosome abnormalities. The maternal serum AFP (MSAFP) tends to be high with open neural tube defects such as anencephaly and spina bifida (meningomyelocele); and low with Down syndrome (trisomy 21, an extra chromosome number 21). AFP production is essentially nil after a year of age. However, it starts up again under the stimulus of some diseases in the liver. It may, for example, be produced by the liver in viral hepatitis and cirrhosis of the liver. AFP is also made by primary liver tumors (hepatomas) and by germ cell tumors (teratocarcinoma and embryonal cell carcinomas). A person's serum AFP level can therefore be used to help detect these conditions and monitor their treatment.

ALS (Amyotrophic Lateral Sclerosis):  A classic motor neuron disease. Motor neuron diseases are progressive chronic diseases of the nerves that come from the spinal cord responsible for supplying electrical stimulation to the muscles. ALS is also known as Lou Gehrig's Disease in North America after the baseball player who had it. Gehrig was born in 1903, and he died in 1941 at the age of 38. ALS strikes in mid-life, most often in the fifth through seventh decades of life. Men are about one-and-a-half times more likely to have the disease as women. It affects about 20,000 Americans at any one time with 5,000 new cases occurring in the United States each year. ALS occurs when specific nerve cells in the brain and spinal cord that control voluntary movement gradually degenerate. The loss of these motor neurons causes the muscles under their control to weaken and waste away, leading to paralysis. The cause of this disease process is still unknown. ALS manifests itself in different ways, depending on which muscles weaken first. Symptoms may include tripping and falling, loss of motor control in hands and arms, difficulty speaking, swallowing and/or breathing, persistent fatigue, and twitching and cramping. ALS is usually progressive and fatal. The usual causes of death of patients with motor neuron diseases are not directly related to the disease, but result from simultaneous additional illnesses, often infections. ALS usually leads to death within 5 years of the time the diagnosis of ALS is made; the range is from 2 to 7 years.

ALT (alanine aminotransferase):  An enzyme normally present in liver and heart cells that is released into the bloodstream when the liver or heart is damaged from, for example, viral hepatitis or a heart attack). Some medications can also raise ALT levels. ALT is also called serum glutamic pyruvic transaminase (SGPT).

Alternative splicing:  Different ways of combining the DNA of a gene so as to create different variants of the protein product of that gene. Alternative splicing is a regulatory mechanism by which variations in the incorporation of a gene's exons, or coding regions, into messenger RNA lead to the production of more than one related protein, or isoform.

Altitude illness:  Altitude illness (or altitude sickness) is a disorder caused by being at high altitude. It commonly occurs above 8,000 feet. The cause of altitude illness is a matter of oxygen pressure. At 12,000 feet there are roughly 40% fewer oxygen molecules per breath. In order to oxygenate the body effectively, breathing rate must increase. This extra ventilation increases the oxygen content in the blood, but not to sea level concentrations. Since the amount of oxygen required for activity is the same, the body must adjust to having less oxygen. In addition, high altitude and lower air pressure cause fluid to leak from the capillaries which can cause fluid build-up in both the lungs and the brain. Continuing to higher altitudes without proper acclimatization can lead to potentially serious, even life-threatening illnesses.

Altitude, acclimatization to: Adjustment to changes in altitude. The main cause of altitude sickness is going too high too fast. Given time, the body can adapt to the decrease in oxygen concentration at a specific altitude, process known as acclimatization. To acclimatize, a number of changes take place in the body occur to allow it to operate with decreased oxygen: the depth of respiration increases; the pressure in the pulmonary arteries increases forcing blood into portions of the lung which are normally not used at sea level; more red blood cells are made; more 2,4-DPG is made which facilitates the release of oxygen from hemoglobin to the body tissues. Acclimatization generally takes 1 to 3 days at a given altitude. Altitude is defined on the following scale:

High altitude: 8,000 - 12,000 feet (2,438 - 3,658 meters);
Very high altitude: 12,000 - 18,000 feet (3,658 - 5,487 meters); and
Extremely high altitude: 18,000+ feet (5,500+ meters).

Most people can go up to 8,000 feet (2,438 meters) with minimal effects. If you have been at that altitude before and had no problems, you can probably return to that altitude without problems if (and only if) you are properly acclimatized..If you have not been to high altitude before, caution is strongly recommended. No specific factors such as age, sex, or physical condition are known to correlate with the susceptibility to altitude sickness. Some people are simply more susceptible than others. There is no telling, so caution is the better part of wisdom..

Alveolar hydatid disease (AHD):  A parasitic disease caused by the larval stage of a microscopic tapeworm Echinococcus multilocularis.

Alveoli:  Tiny air sacs located at the very ends of the bronchioles within the lungs. A single sac is called an alveolus. The exchange of oxygen and carbon dioxide takes place in the alveoli.

Alzheimer disease:  A progressive degenerative disease of the brain that leads to dementia. On a cellular level, Alzheimer disease is characterized by unusual helical protein filaments in nerve cells (neurons) of the brain. These odd twisted filaments are called neurofibrillary tangles. On a functional level, there is degeneration of the cortical regions, especially the frontal and temporal lobes, of the brain. About four million Americans suffer from it, including U.S. President Ronald Reagan. The German psychiatrist and pathologist Alois Alzheimer (1864-1915) first described this form of presenile dementia in 1907.

Amalgam:  In dentistry, an alloy of mercury, silver, tin, etc. used in dental restorations. In susciptible people mercury has proven to provoke degeneration of the immune system, digestive functions, fatigue, and brain fog.

Amastia:  A rare condition wherein the normal growth of the breast or nipple does not occur. Unilateral amastia just on one side is associated with absence of the pectoral muscles. Bilateral amastia is associated in 40% of cases with multiple congenital anomalies involving other parts of the body as well. Amastia is distinguished from amazia (see below)

Amathophobia:  An abnormal and persistent fear of dust. Sufferers experience anxiety even though they realize dust poses no threat. From the Greek "amathos" (sand) and "phobos" (fear).

Amaurosis fugax:  A symptom described as a shade coming down over the eye. A partial or complete loss of sight that is temporary usually related to atherosclerosis in the blood vessels that supply the brain. It can also occur with excessive acceleration, as in flight. Amaurosis is the Greek word for darkening, dark, or obscure. The ancients used it to refer to dimmed vision, especially if there was nothing they could see that was wrong with the eye itself. Fugax is related to fugitive (fleeing). Amaurosis fugax therefore means a fleeting loss of vision.

Amazia:  A condition wherein the breast tissue is absent but the nipple is present. Amazia typically is a result of radiation or surgery.

Amblyopia:  Impaired vision due to lack of use of an eye when the brain favors the other eye. The most common causes of amblyopia are strabismus and anisometropia. In strabismus, the eyes are not aligned. The brain favors one eye over the other and the ignored eye is not adequately stimulated and the visual brain cells do not mature normally. Anisometropia occurs when the eyes have an unequal refractive power. One eye is myopic (nearsighted) and the other hyperopic (farsighted). Because the brain cannot reconcile this difference, it develops a preference for the image coming from one eye only.

Ambulance:  The ambulance began as a walking hospital,"un hôpital ambulant" in French, meaning literally "a walking hospital." The "hôpital ambulant" was devised during the campaigns of Napoleon to bring medical aid directly to troops in the field. The original "hôpital ambulant" was a mobile unit designed to carry dressings and drugs to the wounded and evacuate the injured from the line of battle. The British came up with their own version of the "hôpital ambulant" dropped the "hôpital" and corrupted "ambulant" to "ambulance." The French then rejected their own "hôpital ambulant" and embraced the English "ambulance." So, in France today you can no longer see a hospital walking but "ambulances" are very much in evidence.

Ambulant:  Means the same as "ambulatory," able to ambulate, i.e. walk about.

Ambulatory:  Able to ambulate, to walk about, not bed-ridden or hospitalized.

Ambulatory care:  Medical care provided on an outpatient basis. Ambulatory care is given to persons who are not confined to a hospital but rather are "ambulatory," able to ambulate or walk about.

AMC (arthrogryposis multiplex congenita):  a disorder that develops before birth is evident at birth and involves limited mobility of many (multiple) joints. The range of motion of the joints in the arms and legs is usually limited or fixed. The impairment of joint mobility in AMC is often accompanied by overgrowth of fibrous tissue in the joints with further immobilization of the joints (fibrous ankylosis). The mechanisms responsible for AMC are thought to include: neurologic deficits, muscle defects, connective tissue and skeletal defects, fetal crowding or fetal constraint, and maternal neuromuscular diseases. Arthrogryposis means crooking of the joint. It comes from the Greek "arthro-", joint + "gryposis", crooking. Arthrogryposis multiplex congenita can be translated (very roughly) as "lots of crooked joints at birth."

Ameba (also amoeba):  . A single-celled (protozoan) organism that constantly changes s