Most people on the street have little trouble understanding ordinary English, but even the most fluent English speaker has trouble with medical terminology. Some of the worlds are strange and don’t sound even remotely like what they mean. When you go to a doctor, whether the doctor is a conventional one (allopathic) or an alternative one (holistic), it is important to be able to understand what he (or she) says. Also, when you are written a prescription, whether it is for a conventional (chemical type) medication, or an alternative (natural type) one you may not even be able to understand what it is for.
If you read books about alternatives, particularly aromatherapy, you will need to know several terms that are used throughout when describing the properties of the various oils. When I did the recent essential oil articles I tried not to use too many of these terms without explaining what they were, but you will hear these terms in your life, on the news, at the doctor, and it is better if you know what they are. So here we go!
Useful Medical Glossary (remember this is, by far, not exhaustive, and is a general help when it comes to alternative medicine, if you wish to get more depth in your glossary, then there are several excellent glossaries on the Internet):
Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care.
Allergen: A substance that is foreign to the body and can cause an allergic reaction in certain people. For examples, pollen, dander, mold.
Amenorrhea: Absence or cessation of menstruation. Amenorrhea is conventionally divided into primary and secondary amenorrhea:
- Primary amenorrhea — menstruation never takes place. It fails to occur at puberty.
- Secondary amenorrhea — menstruation starts but then stops.
Analgesic: A drug that relieves pain. With an effective analgesic, there is an inability to feel pain while still conscious.
Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased.
Antibacterial: Anything that destroys bacteria or suppresses their growth or their ability to reproduce. Heat, chemicals such as chlorine, and antibiotic drugs all have antibacterial properties.
Antibiotic: A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another.
Anticoagulant: Any agent used to prevent the formation of blood clots.
Anticonvulsant: A medication used to control (prevent) seizures (convulsions) or stop an ongoing series of seizures.
Antidepressant: Anything, and especially a drug, used to prevent or treat depression.
Antiemetic: 1. As a noun, a drug taken to prevent or treat nausea and vomiting.
2. As an adjective, pertaining to the prevention or treatment of nausea and vomiting.
Antifungal: A drug used to treat fungal infections.
Antihistamines: Drugs that combat the histamine released during an allergic reaction by blocking the action of the histamine on the tissue. Antihistamines do not stop the formation of histamine nor do they stop the conflict between the IgE and antigen. Therefore, antihistamines do not stop the allergic reaction but protect tissues from some of its effects.
Antimicrobial: A drug used to treat a microbial infection.
Antipyretic: Something that reduces fever or quells it.
Antiseptic: Something that discourages the growth microorganisms
Antispasmodic: 1) A medication that lowers the incidence of or prevents seizures. 2) A medication that lowers the incidence of or prevents muscle spasms.
Antiviral: An agent that kills a virus or that suppresses its ability to replicate and, hence, inhibits its capability to multiply and reproduce.
Arrhythmia: An abnormal heart rhythm. In an arrhythmia the heartbeats may be too slow, too rapid, too irregular, or too early. Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias. Slow arrhythmias (slower than 60 beats per minute) are called bradycardias. Irregular heart rhythms are called fibrillations (as in atrial fibrillation and ventricular fibrillation). When a single heartbeat occurs earlier than normal, it is called a premature contraction.
Arteriosclerosis: Hardening and thickening of the walls of the arteries. Arteriosclerosis can occur because of fatty deposits on the inner lining of arteries (atherosclerosis), calcification of the wall of the arteries, or thickening of the muscular wall of the arteries from chronically elevated blood pressure (hypertension).
Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis.
Asphyxia: Impaired or impeded breathing.
Asthma: A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs (alveoli) or the lung tissue (the parenchyma of the lung) itself.
Atherosclerosis: A process of progressive thickening and hardening of the walls of medium-sized and large arteries as a result of fat deposits on their inner lining.
Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Examples of bacteria include:
- Acidophilus, a normal inhabitant of yogurt,
- Chlamydia, which causes an infection very similar to gonorrhea,
- Clostridium welchii the most common cause of the dreaded gas gangrene,
- E. coli, the common peaceful citizen of our colon and, upon occasion, a dangerous agent of disease, and
- Streptococcus, the bacterium that causes the important infection of the throat strep throat.
Bacteriocidal: Capable of killing bacteria. Antibiotics, antiseptics, and disinfectants can be bactericidal.
Basal cells: Small, round cells found in the lower part, or base, of the epidermis, the outer layer of the skin.
Basal metabolic rate: A measure of the rate of metabolism. For example, someone with an overly active thyroid will have an elevated basal metabolic rate.
Beta carotene: A vitamin that acts as an antioxidant, protecting cells against oxidation damage. Beta carotene is converted by the body to vitamin A. Food sources of beta carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots. Excessive carotene in the diet can color the skin yellow, a condition called carotenemia.
Blood clot: Blood that has been converted from a liquid to a solid state. Also called a thrombus.
Blood glucose: The main sugar that the body makes from the food in the diet. Glucose is carried through the bloodstream to provide energy to all cells in the body. Cells cannot use glucose without the help of insulin.
Blood group: An inherited feature on the surface of the red blood cells. A series of related blood types constitute a blood group system such as the Rh or the ABO system.
Blood pH: The acidity or alkalinity of blood. The pH of any fluid is the measure of the hydrogen ion (H–) concentration. A pH of 7 is neutral. The lower the pH, the more acidic the blood. A variety of factors affect blood pH including what is ingested, vomiting, diarrhea, lung function, endocrine function, kidney function, and urinary tract infection. The normal blood pH is tightly regulated between 7.35 and 7.45.
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It’s measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called “hypertension.”).
Blood-thinner: A common name for an anticoagulant agent used to prevent the formation of blood clots. Blood-thinners do not really thin the blood. They prevent it from clotting.
Boil: A skin abscess, a collection of pus localized deep in the skin. A boil usually starts as a reddened, tender area and in time becomes firm and hard. Eventually, the center of the abscess softens and becomes filled with white blood cells that the body sends to fight the infection. This collection of white cells is the pus
Botulism: An uncommon but potentially very serious illness, a type of food poisoning, that produces paralysis of muscles, via a nerve toxin called botulinum toxin (“botox”) that is manufactured by bacteria named Clostridium botulinum. There are various types of botulism, including:
- Food-borne botulism — from eating food that contains the botulinum toxin.
- Wound botulism — caused by the toxin produced in a wound infected with the bacteria Clostridium botulinum.
- Infant intestinal botulism — when an infant consumes the spores of the bacteria, the bacteria grow in the baby’s intestines and release toxin.
- Adult intestinal botulism — due to infection with Clostridium botulinum in adults, typically following abdominal surgical procedures.
The symptoms of botulism can range from mild, including transient nausea and vomiting, to severe cases that progress to heart and lung failure and, sometimes, death. Food-borne botulism occurs typically in unrefrigerated or poorly refrigerated foods and foods without preservatives (especially uncooked or half-cooked meats). It can be prevented by careful use of refrigeration and preservative techniques, and the toxin can be destroyed with heat.
Brown fat: Brown adipose tissue, a rapid source of energy for infants in whom it forms about 5% of their body weight. It is brown because the cells in it are packed full of small cellular organs called mitochondria, which are energy factories, and it has a rich supply of blood vessels. Brown fat is virtually gone by adulthood.
Caffeine: A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea.
Capillary: One of the tiny blood vessels that connect the arterioles (the smallest divisions of the arteries) and the venules (the smallest divisions of the veins). The capillaries form a fine network in many parts of the body.
Although minute, the capillaries are a site where much action takes place in the circulatory system. The walls of the capillaries act as semipermeable membranes permitting the exchange of various substances between the blood stream and the tissues of the body. The substances that are interchanged through the capillary walls include fluids and the key gases oxygen and carbon dioxide.
The word “capillary” originally had more to do with hair than blood vessels. It comes from the Latin “capillaris” = hair-like, which was derived from “capillus” = a hair of the head and “caput” = head.
Carbuncles: A skin abscess, a collection of pus that forms inside the body. Antibiotics are often not very helpful in treating abscesses. The main treatments include hot packs and draining (“lancing”) the abscess, but only when it is soft and ready to drain. If you have a fever or long-term illness, such as cancer or diabetes, or are taking medications that suppress the immune system, you should contact your healthcare practitioner if you develop an abscess.
Carcinogen: A substance or agent that causes cancer.
Cardiac: Having to do with the heart.
Cardiac arrest: A medical emergency with absent or inadequate contraction of the left ventricle of the heart that immediately causes bodywide circulatory failure. The signs and symptoms include loss of consciousness; rapid shallow breathing progressing to apnea (absence of breathing); profoundly low blood pressure (hypotension) with no pulses that can be felt over major arteries; and no heart sounds.
Cardiac arrest is one of the greatest of all medical emergencies. Within several minutes, there is lack of oxygen (tissue hypoxia), leading to multiple organ injury. Unless cardiac arrest is quickly corrected, it is fatal.
Cardiovascular: The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
Cataract: A clouding of the lens of the eye. The normally clear aspirin-sized lens of the eye starts to become cloudy. There are many causes of cataracts including cortisone medication, trauma, diabetes, many other diseases and simply aging. Cataracts will affect almost all people if they are fortunate enough to live long enough. The symptoms of cataracts include double or blurred vision and unusual sensitivity to light and glare. Cataracts can be diagnosed when the doctor examines the eyes with a viewing instrument.
Cathartic: A laxative.
Cellulite: Popular term for deposits of fat that have a cottage cheese-like or puckered texture. Medically, cellulite is not considered abnormal.
Cerebral: Pertaining to the brain, the cerebrum or the intellect.
Cervical: Having to do with any kind of neck including the neck on which the head is perched and the neck of the uterus. The word “cervix” in Latin means “neck”.
Cholesterol: The most common type of steroid in the body, cholesterol has gotten something of a bad name. However, cholesterol is a critically important molecule. It is essential to the formation of:
- Bile acids (which aid in the digestion of fats)
- Vitamin D
- Estrogens (estradiol, estrone, estriol)
- Androgens (androsterone, testosterone)
- Mineralocorticoid hormones (aldosterone, corticosterone) and
- Glucocorticoid hormones (cortisol).
Cholesterol is also necessary to the normal permeability and function of cell membranes, the membranes that surround cells.
Cholesterol is carried in the bloodstream as lipoproteins. Low-density lipoprotein (LDL) cholesterol is the “bad” cholesterol because elevated LDL levels are associated with an increased risk of coronary artery (heart) disease. Conversely, high-density lipoprotein (HDL) cholesterol is the “good” cholesterol since high HDL levels are associated with less coronary disease. After the age of 20, cholesterol testing is recommended every 5 years.
Although some cholesterol is obtained from the diet, most cholesterol is made in the liver and other tissues. The treatment of elevated cholesterol therefore involves not only diet but also weight loss and regular exercise (and, occasionally, medications).
Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. A chronic condition is one lasting 3 months or more, by the definition of the U.S. National Center for Health Statistics. In ancient Greece, the “father of medicine” Hippocrates distinguished diseases that were acute (abrupt, sharp and brief) from those that were chronic. This is still a very useful distinction. Subacute has been coined to designate the mid-ground between acute and chronic.
Circulatory: Having to do with the circulation, the movement of fluid in a regular or circuitous course. Although the adjective “circulatory” need not necessarily refer to the circulation of the blood, for all practical purposes today it does. A circulatory problem is taken usually to be a problem with the blood circulation, for example with heart failure.
Clinical: 1. Having to do with the examination and treatment of patients. 2. Applicable to patients. A laboratory test may be of clinical value (of use to patients). The term comes through the French “clinique” from the Greek “kline” (a couch or bed). Clinical medicine was (and is) practiced at the bedside.
Clinical depression: Depression that meets the DSM-IV criteria for a depressive disorder. The term is usually used to denote depression that is not a normal, temporary mood caused by life events or grieving.
Clinical psychology: A professional specialty concerned with diagnosing and treating diseases of the brain, emotional disturbance, and behavior problems. Psychologists can only use talk therapy as treatment; you must see a psychiatrist or other medical doctor to be treated with medication. Psychologists may have a master’s degree (MA) or doctorate (PhD) in psychology. They may also have other qualifications, including Board certification and additional training in a type of therapy.
Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.
Clinical research trials may be conducted by government health agencies such as NIH, researchers affiliated with a hospital or university medical program, independent researchers, or private industry.
Usually volunteers are recruited, although in some cases research subjects may be paid. Subjects are generally divided into two or more groups, including a control group that does not receive the experimental treatment, receives a placebo (inactive substance) instead, or receives a tried-and-true therapy for comparison purposes.
Typically, government agencies approve or disapprove new treatments based on clinical trial results. While important and highly effective in preventing obviously harmful treatments from coming to market, clinical research trials are not always perfect in discovering all side effects, particularly effects associated with long-term use and interactions between experimental drugs and other medications.
For some patients, clinical research trials represent an avenue for receiving promising new therapies that would not otherwise be available. Patients with difficult to treat or currently “incurable” diseases, such as AIDS or certain types of cancer, may want to pursue participation in clinical research trials if standard therapies are not effective. Clinical research trials are sometimes lifesaving.
There are four possible outcomes from a clinical trial:
- Positive trial — The clinical trial shows that the new treatment has a large beneficial effect and is superior to standard treatment.
- Non-inferior trial — The clinical trial shows that that the new treatment is equivalent to standard treatment. Also called a non-inferiority trial.
- Inconclusive trial — The clinical trial shows that the new treatment is neither clearly superior nor clearly inferior to standard treatment.
- Negative trial — The clinical trial shows that a new treatment is inferior to standard treatment.
Clone: Literally a fragment, the word in modern medical science has come to mean a replica, for example, of a group of bacteria or a macromolecule such as DNA. Clone also refers to an individual developed from a single somatic (non-germ) cell from a parent, representing an exact replica of that parent. A clone is a group of cells derived from a single ancestral cell.
Cluster headache: A distinctive syndrome of headaches, also known as migrainous neuralgia. There are two main clinical patterns of cluster headache — the episodic and the chronic:
- Episodic: This is the most common pattern of cluster headache. It is characterized by 1-3 short attacks of pain around the eyes per day, with these attacks clustered over a stretch of 1-2 months followed by a pain-free remission, a breathing spell. The average length of remission is a year.
- Chronic: Characterized by the absence of sustained periods of remission, chronic cluster headache may start with no past history of cluster headaches, or it may emerge several years after the patient has experienced an episodic pattern of cluster headaches.
The episodic and acute forms of cluster headache may transform into one another, so it seems most likely that they are merely different-appearing clinical patterns of one and the same disease.
Although the mechanisms underlying cluster headache and migraine may have a degree of commonality, cluster headache looks to be different and distinct as a disease from migraine. For example, propranolol is effective for migraine but not cluster headache while lithium benefits cluster headache syndrome but not migraine.
Coagulation: In medicine, the clotting of blood. The process by which the blood clots to form solid masses, or clots.
More than 30 types of cells and substances in blood affect clotting. The process is initiated by blood platelets. Platelets produce a substance that combines with calcium ions in the blood to form thromboplastin, which in turn converts the protein prothrombin into thrombin in a complex series of reactions. Thrombin, a proteolytic enzyme, converts fibrinogen, a protein substance, into fibrin, an insoluble protein that forms an intricate network of minute threadlike structures called fibrils and causes the blood plasma to gel. The blood cells and plasma are enmeshed in the network of fibrils to form the clot.
Cognitive: Pertaining to cognition, the process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging. The study of cognition touches on the fields of psychology, linguistics, computer science, neuroscience, mathematics, ethology and philosophy.
Congenital: Present at birth. A condition that is congenital is one that is present at birth. There are numerous uses of “congenital” in medicine. There are, for example, congenital abnormalities.
Versus “genetic”: One dictionary erroneously defines “congenital” as meaning: “Occurring prior to birth, due to parent’s genetic input.” Congenital does not mean genetic. Something that is congenital may or may not be genetic (inherited). For example, congenital syphilis is present at birth but is not genetic.
Timing: Something that is congenital may or may not occur “prior to birth.” The essential feature is that it is there at birth (if not before).
Etymology: Congenital comes from the Latin congenitus which is made up of com-, with + genitus, the past participle of gignere, to bring forth. The word “congenital” has not been used in English since its birth but first appeared in 1796. The term “congenital” is synonymous with “innate.”
Cosmeceutical: A cosmetic product claimed to have medicinal or drug-like benefits. Cosmeceutical products are marketed as cosmetics, but reputedly contain biologically active ingredients. Examples include anti-wrinkle skin creams with ingredients such as alpha lipoic acid and dimethylaminoethanol and creams containing “cellular replenishment serum” that supposedly have “antiaging properties.”
Cutaneous: Relating to the skin.
Cyst: A cyst is an abnormal, closed sac-like structure within a tissue that contains a liquid, gaseous, or semisolid substance. A cyst can occur anywhere in the body and can vary in size. The outer, or capsular, portion of a cyst is termed the cyst wall.
Cystitis: Inflammation of the bladder. Cystitis can be due for example to infection from bacteria that ascend the urethra (the canal from the outside) to the bladder.
Symptoms include a frequent need to urinate, often accompanied by a burning sensation. As cystitis progresses, blood may be observed in the urine and the patient may suffer cramps after urination. In young children, attempts to avoid the pain of cystitis can be a cause for daytime wetting (enuresis). Treatment includes avoiding irritants, such as perfumed soaps, near the urethral opening; increased fluid intake; and antibiotics. Untreated cystitis can lead to scarring and the formation of stones when urine is retained for long periods of time to avoid painful urination.
Dandruff: A mild skin condition that produces white flakes that may be shed and fall from the hair.
Dandruff is due to the sebaceous glands overworking. (The sebaceous glands keep the skin properly oiled.)
Another cause of dandruff is fungus, especially one called Pitrosporum ovale. (Most people have this fungus, but people with dandruff have more.)
For dandruff, there are several tiers of treatment:
- First-tier dandruff treatment: A good quality upper-end shampoo (e.g., Paul Mitchell, Aveda, Redken). If several weeks using a good quality shampoo does not stop the dandruff, it can be helpful use the second-tier of dandruff treatment.
- Second-tier dandruff treatment: An antifungal shampoo, (e.g., (in alphabetical order) Denorex, DHS Targel, ionil-T plus, MG217, Neutrogena T/Gel, Scalpicin, Sebulex, Selsun Blue, Tegrin, Zircon).
Decongestant: A drug that shrinks the swollen membranes in the nose and makes it easier to breath. Decongestants can be taken orally or by nasal spray. Decongestant nasal sprays should not be used for more than five days without the doctor’s advice, and if so, usually only when accompanied by a nasal steroid. Many decongestant nasal sprays often cause a rebound effect if taken too long. A rebound effect is the worsening of symptoms when a drug is discontinued. This is a result of a tissue dependence on the medication. Decongestants should not be used by patients with high blood pressure (hypertension) unless under doctor’s supervision.
Dehydration: Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).
Dehydration: Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).
Depression: An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely “pull themselves together” and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
Dermal: Pertaining to the skin. From the Greek word derma for skin.
Dermatitis: Inflammation of the skin, either due to direct contact with an irritating substance, or to an allergic reaction. Symptoms of dermatitis include redness, itching, and in some cases blistering.
Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name “diabetes” because they are both conditions characterized by excessive urination (polyuria).
The word “diabetes” is borrowed from the Greek word meaning “a siphon.” The 2nd-century A.D. Greek physician, Aretus the Cappadocian, named the condition “diabetes.” He explained that patients with it had polyuria and “passed water like a siphon.”
When “diabetes” is used alone, it refers to diabetes mellitus. The two main types of diabetes mellitus — insulin-requiring type 1 diabetes and adult-onset type 2 diabetes — are distinct and different diseases in themselves.
Diuretic: Anything that promotes the formation of urine by the kidney. (The word “diuretic” comes from a combination of the Greek “dia-“, thoroughly + “ourein”, to urinate = to urinate thoroughly).
Diuresis may be due to a huge number of causes including metabolic conditions such as diabetes mellitus (in which the increased glucose level in the blood causes water to be lost in the urine); substances in food and drink (such as coffee, tea, and alcoholic beverages); and specific diuretic drugs.
All diuretic drugs — which are usually called, more simply, diuretics — cause a person to “lose water” but they do so by diverse means, including:
- Inhibiting the kidney’s ability to reabsorb sodium, thus enhancing the loss of sodium in the urine. And when sodium is lost in the urine, water goes with it. (This type of diuretic is called a high-ceiling diuretic or a loop diuretic).
- Enhancing the excretion of both sodium and chloride in the urine so that water is excreted with them. This is how the thiazide diuretics work.
- Blocking the exchange of sodium for potassium, resulting in excretion of sodium and potassium but relatively little loss of potassium. These diuretics are therefore termed potassium sparing diuretics.
Some diuretics work by still other mechanisms. And some diuretics have other effects and uses such as in treating hypertension.
Dropsy: An old term for the swelling of soft tissues due to the accumulation of excess water.
Edema is often more prominent in the lower legs and feet toward the end of the day as a result of pooling of fluid from the upright position usually maintained during the day. Upon awakening from sleeping, people can have swelling around the eyes referred to as periorbital edema.
Dyspepsia: Dyspepsia refers to a condition (disease) in which there are upper abdominal symptoms which may include upper abdominal pain, bloating (a feeling of abdominal fullness without objective abdominal distention), early satiety (a feeling of unusual fullness with very little intake of food), nausea, or belching. The symptoms often are provoked by eating.
Dyspepsia is considered a functional disease. (Another functional disease is irritable bowel syndrome or IBS.) Functional diseases are diseases in which no abnormalities can be seen anatomically, for example, on x-rays, or histologically under the microscope. The abnormalities are believed to be due to altered function, primarily of the muscles and nerves of the gastrointestinal tract.
E. coli: Short for Escherichia coli, the colon bacillus, a bacterium that normally resides in the human colon. E. coli has been studied intensively in genetics and molecular and cell biology because of its availability, its small genome size, its normal lack of pathogenicity (disease-causing ability), and its ease of growth in the laboratory. Most strains of E coli are quite harmless. However, some strains of E. coli are capable of causing disease, sometimes disease of deadly proportions. For example, an outbreak of E. coli O157:H7 bacteria in the water supply hit Walkerton, Ontario in the year 2000; the E. coli affected about 2,000 people in and around Walkerton and were responsible for the deaths of some 18 people. E. coli 0157:H7 is a major health problem. About 20,000 cases of hemorrhagic (bloody) colitis (inflammation of the bowel) due to E. coli 0157:H7 occur each year in the U.S. E coli O157:H7 produces toxins (poisons). The toxins produced by E. coli 0157:H7 can damage the lining of the intestine and are thought to participate in all of the diseases caused by E. coli 0157:H7. The hemorrhagic diarrhea (bloody colitis) caused by E. coli 0157:H7 is severe with painful abdominal cramps, gross blood in the stool, and lasts for 6 to 8 days. Children with E. coli 0157:H7 can develop a disease called the hemolytic-uremic syndrome (HUS), a major and sometimes fatal “Hemolytic” refers to the breakup of red blood cells. This leads to anemia and a shortage of platelets (thrombocytopenia) which causes abnormal bleeding. “Uremic” refers to the acute kidney failure. Central nervous system problems with seizures and coma can also occur. HUS is the most common cause of acute kidney failure in infants and young children.Persons who get E. coli 0157:H7, particularly the elderly, can develop a syndrome similar to HUS called thrombotic thrombocytopenic purpura (TTP) with anemia due to fragmentation of red blood cells, shortage of platelets (thrombocytopenia) with easy bruising, neurologic abnormalities, impaired kidney function, and fever. Most commonly, E. coli 01257:H7 comes from eating raw or undercooked ground beef (hamburger) or from drinking raw milk or contaminated water. Less commonly, E coli O157:H7 can be transmitted from one person to another.
EEG: Electroencephalogram, e technique for studying the electrical current within the brain. Electrodes are attached to the scalp. Wires attach these electrodes to a machine which records the electrical impulses. The results are either printed out or displayed on a computer screen. Electroencephalogram is abbreviated EEG.
Electrolyte: An electrolyte is a substance that will dissociate into ions in solution and acquire the capacity to conduct electricity. The electrolytes include sodium, potassium, chloride, calcium and phosphate. Informally, called lytes. (The clue to the word electrolyte is in the lyte which comes from the Greek lytos meaning that may be dissolved.)
Embolism: The obstruction of a blood vessel by a foreign substance or a blood clot blocking the vessel. Something travels through the bloodstream, lodges in a vessel and plugs it.
Foreign substances that can cause embolism include an air bubble, amniotic fluid, a globule of fat, a clump of bacteria, chemicals (such as talc), and drugs (mainly illicit ones).
Blood clots are the most common cause of embolism. A pulmonary embolus is a blood clot that has been carried through the blood into the pulmonary artery (the main blood vessel from the heart to the lung) or one of its branches, plugging that vessel.
article about a medical subject.
Emetic: Something that causes emesis, that makes you want to vomit. For example, ipecac is an emetic. From the Greek emein (to vomit), from the Indo-European root wem- (to vomit), the source of the words such as wamble (to feel nauseated) and vomit.
Empirical: Based on experience and observation, rather than systematic logic. Experienced physicians often use empirical reasoning to make diagnoses, based on having seen many cases over the years. Less-experienced physicians are more likely to use diagnostic guides and manuals. In practice, both approaches (if properly applied) will usually come up with the same diagnosis.
Endemic: Present in a community at all times but in relatively low frequency. Something that is endemic is typically restricted or peculiar to a locality or region.
Epidemic: The occurrence of more cases of a disease than would be expected in a community or region during a given time period. A sudden severe outbreak of a disease such as SARS. From the Greek “epi-“, “upon” + “demos”, “people or population” = “epidemos” = “upon the population.” See also: Endemic; Pandemic.
Essential fatty acid: An unsaturated fatty acid that is essential to human health, but cannot be manufactured in the body. There are three types of essential fatty acids (EFAs): arachnoidic acid, linoleic acid, and linolenic acid. When obtained in the diet, linoleic acid can be converted to both arachnoidic and linolenic acid. It is commonly found in cold-pressed oils, and is particularly high in oils extracted from cold-water fish and certain seeds. Recent research has explored the role of EFAs in the nervous system health. Supplementation with certain EFOs appears to be useful as a treatment for certain neurological disorders. However, arachnoidic acid may lower the seizure threshold. For that reason, always consult a knowledgeable physician before starting a program of EFA supplementation.
Essential oil: An oil derived from a natural substance, usually either for its healing properties or as a perfume. Some pharmaceuticals, and many over-the-counter or “holistic” remedies, are based on or contain essential oils. Examples include products containing camphor or eucalyptus that help relieve congestive coughs, and the essential oils used in the practice of aromatherapy.
Exacerbate: To make worse.
Expectorant: A medication that helps bring up mucus and other material from the lungs, bronchi, and trachea. An example of as expectorant is guaifenesin which promotes drainage of mucus from the lungs by thinning the mucus and also lubricates the irritated respiratory tract. Sometimes the term “expectorant” is incorrectly extended to any cough medicine. From the Latin expectorare, to expel from the chest, from ex-, out of + pectus, chest.
Fascia: A flat band of tissue below the skin that covers the underlying tissues and separates different layers of tissue. Fascia encloses muscles. Inflammation of the fascia is referred to as fasciitis.
Fat, saturated: A fat that is solid at room temperature and comes chiefly from animal food products. Some examples are butter, lard, meat fat, solid shortening, palm oil, and coconut oil. These fats tend to raise the level of cholesterol in the blood.
Fat, trans: An unhealthy substance, also known as trans fatty acid, made through the chemical process of hydrogenation of oils. Hydrogenation solidifies liquid oils and increases the shelf life and the flavor stability of oils and foods that contain them. Trans fat is found in vegetable shortenings and in some margarines, crackers, cookies, snack foods and other foods.
Trans fats are also found in abundance in “french fries.” To make vegetable oils suitable for deep frying, the oils are subjected to hydrogenation, which creates trans fats. Among the hazards of fast food, “fries” are prime in purveying trans fats.
Trans fats wreak havoc with the body’s ability to regulate cholesterol. In the hierarchy of fats, the polyunsaturated fats which are found in vegetables are the good kind; they lower your cholesterol. Saturated fats have been condemned as the bad kind. But trans fats are far worse. They drive up the LDL (“bad”) cholesterol. which markedly increases the risk of coronary artery heart disease and stroke. According to a recent study of some 80,000 women, for every 5% increase in the amount of saturated fat a woman consumes, her risk of heart disease increases by 17%. But only a 2% increase in trans fats will increase her risk of heart disease by 93%!
The US FDA in 1999 proposed that the Nutrition Facts labels on vegetable shortenings and some cookies, crackers, margarines, and other foods may soon carry information about trans fatty acids, or trans fats. Beyond requiring that some labels list the amount of trans fats in the food, the FDA rule would also define the term “trans fat free” and limits the use of certain nutrient or health claims related to fat content, such as “lean” and “low saturated fat.”
In the realm of dietary dangers, trans fats rank very high. It has been estimated that trans fats are responsible for some 30,000 early deaths a year in the United States. Worldwide the toll of premature deaths is in the millions.
Fatigue: A condition characterized by a lessened capacity for work and reduced efficiency of accomplishment, usually accompanied by a feeling of weariness and tiredness. Fatigue can be acute and come on suddenly or chronic and persist.
Fatty acid: One of many molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes as a component of phospholipids and glycolipids. (Carboxylic acid is an organic acid containing the functional group -COOH.)
Fatty acids come from animal and vegetable fats and oils. Fatty acids play roles outside the body; they are used as lubricants, in cooking and food engineering, and in the production of soaps, detergents, and cosmetics.
Flatulence: Excess gas in the intestinal tract.
Flora: The population of microbes inhabiting the outside or inside surfaces of people (or other animals). Also, the population of plants including flowers, usually in a particular area.
Freckle: A flat circular spot on the skin about the size of the head of a nail that develops after repeated exposure to sunlight, particularly in someone of fair complexion. Freckles may be red, yellow, tan, light-brown, brown, or black. They are always darker than the skin around them since they are due to deposits of the dark melanin, a dark pigment.
There are two basic types of freckles — ephelides and lentigines. Ephelides (singular: ephelis) are flat red or light-brown spots that typically appear during the sunny months and fade in the winter. Lentigines (singular: lentigo) are small tan, brown, or black spots which tend to be darker than an ephelis-type freckle and which do not fade in the winter.
The sun is not the only factor that induces freckles. Heredity also influences freckling, as witnessed by the striking similarity in the total number of freckles on identical twins. Such similarities are considerably less marked in fraternal twins. A gene for freckles has been mapped to chromosome 4q32-q34.
Freckles are harmless. They may sometimes be confused with more serious skin problems. Conversely, more serious problems such as skin cancer may at times be passed over as a mere freckle. Anyone who has one or more pigmented spots of which they are not certain should be seen by a physician (or dermatologist). Effective treatments are available to lighten or eliminate those freckles whose appearance bothers their owners.
Fungal: Pertaining to a fungus. For example, a fungal skin infection.
The word “gangrene” comes from the Greek “ganggraina” denoting “an eating sore that ends in mortification” (of the flesh).
Gas gangrene involves the invasion of a deep penetrating wound (in which the blood supply is compromised) by anaerobic bacteria (bacteria that can survive with little or no oxygen) such as members of Clostridium family of bacteria. The bacteria generate gas and pus. Gas gangrene is an acute, painful, dangerous condition.
Dry gangrene is the death of tissue due to vascular insufficiency without bacterial invasion. The tissue simply dries up and shrivels.
Gastric: Having to do with the stomach.
Generic: 1. The chemical name of a drug. 2. A term referring to the chemical makeup of a drug rather than to the advertised brand name under which the drug may be sold. 3.A term referring to any drug marketed under its chemical name without advertising.
Generic drugs marketed without brand names are generally less expensive than brand-name drugs, even though they are chemically identical to brand-name drugs and meet the same standards of the FDA (US Food and Drug Administration) for safety, purity and effectiveness. Generic drugs can be legally produced in the US if a patent has expired, or for drugs which have never been patented. The expiration of a patent removes the monopoly of the patent holder on drug sales licensing.