Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).
Absorption: Uptake. In the biomedical sciences, absorption has diverse specific meanings. See the entire definition of Absorption
ACE inhibitors: A drug that inhibits ACE (angiotensin converting enzyme) which is important to the formation of angiotensin II. Angiotensin II causes arteries in the body to constrict and thereby raises the blood pressure. ACE inhibitors lower the blood pressure by inhibiting the formation of angiotensin II. This relaxes the arteries. Relaxing the arteries not only lowers blood pressure, but also improves the pumping efficiency of a failing heart and improves cardiac output in patients with heart failure. ACE inhibitors are therefore used for blood pressure control and congestive heart failure. See the entire definition of ACE inhibitors
Acetaminophen: A pain reliever and fever reducer. Brand name: Tylenol. The exact mechanism of action of acetaminophen is not known. Acetaminophen relieves pain by elevating the pain threshold (that is, by requiring a greater amount of pain to develop before it is felt by a person). Acetaminophen reduces fever through its action on the heat-regulating center (the "thermostat") of the brain. Generic is available.
Adrenal gland: One of 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). See the entire definition of Adrenal gland
Aging: The process of becoming older, a process that is genetically determined and environmentally modulated. See the entire definition of Aging
Albuginea: Tough white fibrous tissue. The tunica albuginea of the testis, for example, is the layer of dense whitish inelastic tissue that surrounds the testis.
Alcohol abuse: Use of alcoholic beverages to excess, either on individual occasions ("binge drinking") or as a regular practice. For some individuals-children or pregnant women, for example-almost any amount of alcohol use may be legally considered "alcohol abuse," depending on local laws. Heavy alcohol abuse can cause physical damage and death.
Alcoholism: Physical dependence on alcohol to the extent that stopping alcohol use will bring on withdrawal symptoms. In popular and therapeutic parlance, the term may also be used to refer to ingrained drinking habits that cause health or social problems. Treatment requires first ending the physical dependence, then making lifestyle changes that help the individual avoid relapse. In some cases, medication or hospitalization are needed. Alcohol dependence can have many serious effects on the brain, liver, and other organs of the body.
Alpha blocker: A drug that blocks receptors in arteries and smooth muscle. This action relaxes the blood vessels and leads to an increase in blood flow and a lower pressure for the control of hypertension. The action in the urinary tract enhances urinary flow in prostatic hypertrophy (enlarged prostate). The alpha blockers include doxazosin (Cardura), prazosin (Minipress), and The alpha blockers include doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin).
Ambulatory: Able to ambulate, to walk about, not bed-ridden or hospitalized.
Amitriptyline: An antidepressant medication. In some patients with depression, abnormal levels of brain chemicals called neurotransmitters may relate to the depression. Amitriptyline elevates mood by raising the level of neurotransmitters in brain tissue. Amitriptyline is also a sedative that is useful for depressed patients with insomnia, restlessness, and nervousness. It is sometimes used to treat fibromyalgia and symptoms related to chronic pain. Brand names are Elavil and Endep. A generic version is available.
Anatomy: The study of form. Gross anatomy involves structures that can be seen with the naked eye. It is as opposed to microscopic anatomy (or histology) which involves structures seen under the microscope. Traditionally, both gross and microscopic anatomy have been studied in the first year of medical school in the U.S. The most celebrated textbook of anatomy in the English-speaking world is Gray's Anatomy, still a useful reference book. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The abbreviation for anatomy is anat.
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. See the entire definition of Anemia
Angina: Chest pain due to an inadequate supply of oxygen to the heart muscle. The chest pain of angina is typically severe and crushing. There is a feeling just behind the breastbone (the sternum) of pressure and suffocation. See the entire definition of Angina
Angiogram: An x-ray of blood vessels which can be seen because the patient receives an injection of dye to outline the vessels on the x-ray.
Angiotensin: A family of peptides (smaller than proteins) that act as vasoconstrictors to narrow blood vessels.
Angiotensin converting enzyme: Usually abbreviated ACE.
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. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks. See the entire definition of Antibiotic
Antidepressants: Anything, and especially a drug, used to prevent or treat depression. See the entire definition of Antidepressants
Antigen: A substance that is capable of causing the production of an antibody. See the entire definition of Antigen
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. Antihistamines frequently cause mouth dryness and sleepiness. Newer "non sedating" antihistamines are generally thought to be somewhat less effective. Antihistamine side effects that very occasionally occur include urine retention in males and fast heart rate.
Antipsychotic: A medication (or another measure) that is believed to be effective in the treatment of psychosis. For example, aripiprazole (Abilify) is an antipsychotic medication used to treat schizophrenia.
Anxiety: A feeling of apprehension and fear characterized by physical symptoms such as palpitations, sweating, and feelings of stress. Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. These disorders fill people's lives with overwhelming anxiety and fear. Unlike the relatively mild, brief anxiety caused by a stressful event such as a business presentation or a first date, anxiety disorders are chronic, relentless, and can grow progressively worse if not treated. See the entire definition of Anxiety
Aortic: Pertaining to the aorta, the largest artery in the body. See the entire definition of Aortic
Aortic stenosis: Narrowing (stenosis) of the heart valve between the left ventricle of the heart and the aorta. This narrowing impedes the delivery of blood through the aorta to the body and makes it tough for the heart to carry out this Herculean task. A normal aortic valve has three leaflets or cusps, but a stenotic valve may have only one cusp (unicuspid) or two cusps (bicuspid), which are thick. stiff and stenotic. Some children with aortic stenosis have chest pain, unusual fatigue, dizziness or fainting. Many children have few or no symptoms. The need for surgery depends on the degree of stenosis. Although surgery may enlarge the stenotic valve the valve remains deformed and eventually may need to be replaced with an artificial one. A procedure called balloon valvuloplasty has been used in some children with aortic stenosis. Persons with aortic stenosis need medical follow-up all their lives since even mild stenosis may worsen over time and need treatment.
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).
Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red. See the entire definition of Artery
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. See the entire definition of Atherosclerosis
Atrophy: Wasting away or diminution. Muscle atrophy is wasting of muscle, decrease in muscle mass. See the entire definition of Atrophy
Back pain: Pain felt in the low or upper back. There are many causes of back pain. See the entire definition of Back pain
Benign: Not cancer. Not malignant. A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place). See the entire definition of Benign
Beta blocker: A class of drugs that block beta-adrenergic substances such as adrenaline (epinephrine) in the "sympathetic" portion of the autonomic (involuntary) nervous system. By blocking the action of the sympathetic nervous system on the heart, beta blockers relieve stress on the heart; they slow the heart beat, lessen the force with which the heart muscle contracts, and reduce blood vessel contraction in the heart, brain, and throughout the body. Beta blockers may be used to treat abnormal heart rhythms (cardiac arrhythmias) and prevent abnormally fast heart rates (tachycardias) or irregular heart rhythms such as premature ventricular beats. Since beta blockers reduce the demand of the heart muscle for oxygen and the chest pain of angina pectoris occurs when the oxygen demand of the heart exceeds the supply, beta blockers can be useful in treating angina. They have also become an important drug in improving survival after a person has had a heart attack. Thanks to their effect on blood vessels, beta blockers can lower the blood pressure and be of value in the treatment of hypertension. Other uses for beta blockers include the prevention of migraine headaches and the treatment of certain types of tremors (familial or hereditary essential tremors). See the entire definition of Beta blocker
Bladder: Any pouch or other flexible enclosure that can hold liquids or gases but usually refers to the hollow organ in the lower abdomen that stores urine -- the urinary bladder. The kidneys filter waste from the blood and produce urine, which enters the bladder through two tubes called ureters. Urine leaves the bladder through another tube, the urethra. In women, the urethra is a short tube that opens just in front of the vagina. In men, it is longer, passing through the prostate gland and then the penis. Infection of the bladder is called cystitis.
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. See the entire definition of Blood glucose
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".
Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
Bypass: An operation in which a surgeon creates a new tubular pathway for the movement of fluids and/or other substances in the body.
Calcium: A mineral found mainly in the hard part of bones, where it is stored. Calcium is added to bones by cells called osteoblasts and is removed from bones by cells called osteoclasts. Calcium is essential for healthy bones. It is also important for muscle contraction, heart action, nervous system maintenance, and normal blood clotting. Food sources of calcium include dairy foods, some leafy green vegetables such as broccoli and collards, canned salmon, clams, oysters, calcium-fortified foods, and tofu. According to the National Academy of Sciences, adequate intake of calcium is 1,200 milligrams a day (four glasses of milk) for men and women 51 and older, 1,000 milligrams a day for adults 19 through 50, and 1,300 milligrams a day for children 9 through 18. The upper limit for calcium intake is 2.5 grams daily.
Learn more about calcium with evidence-based information on RxList.
Cancer: An abnormal growth of cells which tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread). See the entire definition of Cancer
Cardiac: Having to do with the heart.
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. See the entire definition of Cardiovascular
Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane. See the entire definition of Cell
Cerebral: Pertaining to the brain, the cerebrum or the intellect. See the entire definition of Cerebral
Cheek: The side of the face forming the side wall of the mouth. See the entire definition of Cheek
Chest: The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum. See the entire definition of Chest
Chest pain: There are many causes of chest pain. One is angina which results from inadequate oxygen supply to the heart muscle. Angina can be caused by coronary artery disease or spasm of the coronary arteries. Chest pain can also be due to a heart attack (coronary occlusion) and other important diseases such as, for example, dissection of the aorta and a pulmonary embolism. Do not try to ignore chest pain and "work (or play) though it." Chest pain is a warning to seek medical attention.
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. See the entire definition of Cholesterol
Circulation: The movement of fluid in a regular or circuitous course. Although the noun "circulation" does not necessarily refer to the circulation of the blood, for all practical purposes today it does. Heart failure is an example of a problem with the circulation.
Cirrhosis: An abnormal liver condition characterized by irreversible scarring of the liver. Alcohol and viral hepatitis B and C are among the many causes of cirrhosis. Cirrhosis can cause yellowing of the skin (jaundice), itching, and fatigue. Diagnosis of cirrhosis can be suggested by physical examination and blood tests, and can be confirmed by liver biopsy in some patients. Complications of cirrhosis include mental confusion, coma, fluid accumulation (ascites), internal bleeding, and kidney failure. Treatment of cirrhosis is designed to limit any further damage to the liver as well as complications. Liver transplantation is becoming an important option for patients with advanced cirrhosis.
Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people. See the entire definition of Clinical trials
Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America. See the entire definition of Cocaine
Colon: The part of the large intestine that runs from the cecum to the rectum as a long hollow tube that serves to remove water from digested food and let the remaining material, solid waste called stool, move through it to the rectum and leave the body through the anus. . See the entire definition of Colon
Colon cancer: A malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colonic polyps. Removal of these precancerous polyps can prevent colon cancer. See the entire definition of Colon cancer
Congestion: An abnormal or excessive accumulation of a body fluid. The term is used broadly in medicine. Examples include nasal congestion (excess mucus and secretions in the air passages of the nose) seen with a common cold and congestion of blood in the lower extremities seen with some types of heart failure.
Congestive heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. See the entire definition of Congestive heart failure
Coronary arteries: The vessels that supply the heart muscle with blood rich in oxygen. They are called the coronary arteries because they encircle the heart in the manner of a crown. The word "coronary" comes from the Latin "corona" and Greek "koron" meaning crown. Like other arteries, the coronaries may be subject to arteriosclerosis (hardening of the arteries). There are a number of coronary arteries. Those most often bypassed today include the right coronary artery, the posterior descending coronary artery, the left main coronary artery, the left anterior descending coronary artery and the left circumflex coronary artery. Plaques obstructing the coronary arteries may also be treated by balloon angioplasty, stents, and other techniques.
Coronary artery disease: A major cause of illness and death, coronary artery disease (CAD) begins when hard cholesterol substances (plaques) are deposited within a coronary artery. See the entire definition of Coronary artery disease
Corpora cavernosa: Two chambers in the penis which run the length of the organ and are filled with spongy tissue. Blood flows in and fills the open spaces in the spongy tissue to create an erection.
Cortisol: The primary stress hormone. Cortisol is the major natural GLUCOCORTICOID (GC) in humans.
Creatine: A compound the body synthesizes (makes) and then utilizes to store energy. The storage of energy occurs when phosphate molecules are attached to creatine to create creatine phosphate. Creatine phosphate is capable of donating phosphate to ADP in order to make ATP. ATP can then be converted into ADP with release of energy. See the entire definition of Creatine
Creatinine: A chemical waste molecule that is generated from muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body's creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and dispose of it in the urine. See the entire definition of Creatinine
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. See the entire definition of Depression
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). See the entire definition of Diabetes
Diabetes mellitus: Better known just as "diabetes" -- a chronic disease associated with abnormally high levels of the sugar glucose in the blood. Diabetes is due to one of two mechanisms: (1) Inadequate production of insulin (which is made by the pancreas and lowers blood glucose) or (2) Inadequate sensitivity of cells to the action of insulin. The two main types of diabetes correspond to these two mechanisms and are called insulin dependent (type 1) and non-insulin dependent (type 2) diabetes. In type 1 diabetes there is no insulin or not enough of it. In type 2 diabetes, there is generally enough insulin but the cells upon it should act are not normally sensitive to its action. See the entire definition of Diabetes mellitus
Diabetic neuropathy: A family of nerve disorders caused by diabetes. Diabetic neuropathies cause numbness and sometimes pain and weakness in the hands, arms, feet, and legs. Neurologic problems in diabetes may occur in every organ system, including the digestive tract, heart, and genitalia. People with diabetes can develop nerve problems at any time, but the longer a person has diabetes, the greater is the risk. See the entire definition of Diabetic neuropathy
Diagnosis:1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Dialysis: The process of cleansing the blood by passing it through a special machine. Dialysis is necessary when the kidneys are not able to filter the blood. Dialysis allows patients with kidney failure a chance to live productive lives. There are two types of dialysis: hemodialysis and peritoneal dialysis. Each type of dialysis has advantages and disadvantages. Patients can often choose the type of long term dialysis that best matches their needs.
Diarrhea: A familiar phenomenon with unusually frequent or unusually liquid bowel movements, excessive watery evacuations of fecal material. The opposite of constipation. The word "diarrhea" with its odd spelling is a near steal from the Greek "diarrhoia" meaning "a flowing through." Plato and Aristotle may have had diarrhoia while today we have diarrhea. There are myriad infectious and noninfectious causes of diarrhea. See the entire definition of Diarrhea
Dilation: The process of enlargement, stretching, or expansion. The word "dilatation" means the same thing. Both come from the Latin "dilatare" meaning "to enlarge or expand."
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). See the entire definition of Diuretic
Dizziness: Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo. See the entire definition of Dizziness
Drain: A device for removing fluid from a cavity or wound. A drain is typically a tube or wick. As a verb, to allow fluid to be released from a confined area.
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. See the entire definition of Dyspepsia
Ejaculate: To ejaculate is to release semen during an orgasm in a male. See the entire definition of Ejaculate
Electrocardiogram: A recording of the electrical activity of the heart. An electrocardiogram is a simple, non-invasive procedure. Electrodes are placed on the skin of the chest and connected in a specific order to a machine that, when turned on, measures electrical activity all overaround the heart. Output is usually in the form of a long scroll of paper displaying a printed graph of activity. Newer models output the data directly to a computer and screen, although a print-out may still be made. See the entire definition of Electrocardiogram
Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions, converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist. See the entire definition of Enzyme
Enzymes: Proteins that act as a catalysts in mediating and speeding a specific chemical reaction. See the entire definition of Enzymes
Erectile dysfunction: A common men's health problem characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Impotence can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent ability to do so, or a tendency to sustain only very brief erections. Erectile dysfunction is also called impotence, See the entire definition of Erectile dysfunction
Erythromycin:Erythromycin is a common antibiotic for treating bacterial infection. Sold under many brand names, including EES, Erycin and Erythromia.
Essential:1. Something that cannot be done without. 2. Required in the diet, because the body cannot make it. As in an essential amino acid or an essential fatty acid. 3. Idiopathic. As in essential hypertension. "Essential" is a hallowed term meaning "We don't know the cause."
Family history: The family structure and relationships within the family, including information about diseases in family members. See the entire definition of Family history
FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services. See the entire definition of FDA
Fracture: A break in bone or cartilage. Although usually the result of trauma, a fracture can be caused by an acquired disease of bone such as osteoporosis or by abnormal formation of bone in a disease such as osteogenesis imperfecta ("brittle bone disease"). Fractures are classified according to their character and location as, for example, a greenstick fracture of the radius. See the entire definition of Fracture
Gene: The basic biological unit of heredity. A segment of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Gene
Gland:1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.
Glucose: The simple sugar (monosaccharide) that serves as the chief source of energy in the body. Glucose is the principal sugar the body makes. The body makes glucose from proteins, fats and, in largest part, carbohydrates. Glucose is carried to each cell through the bloodstream. Cells, however, cannot use glucose without the help of insulin. Glucose is also known as dextrose. See the entire definition of Glucose
Gonad: A reproductive gland (ovary or testis) that produces germ cells (gametes). See the entire definition of Gonad
Gynecomastia: Excessive development of the male breasts. Temporary enlargement of the breasts is not unusual or abnormal in boys during adolescence or during recovery from malnutrition. Gynecomastia may be abnormal as, for example, in Klinefelter's syndrome. See the entire definition of Gynecomastia
Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes. See the entire definition of Headache
Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest. See the entire definition of Heart
Heart attack: The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue. See the entire definition of Heart attack
Heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart. See the entire definition of Heart failure
Heart muscle: A type of muscle with unique features only found in the heart. The heart muscle, or cardiac muscle, is medically called the myocardium ("myo-" being the prefix denoting muscle).
Heart valves: There are four heart valves. All are one-way valves. Blood entering the heart first passes through the tricuspid valve and then the pulmonary valve. After returning from the lungs, the blood passes through the mitral (bicuspid) valve and exits via the aortic valve.
Hemochromatosis:Hemochromatosis (iron overload) is an inherited disorder in how the body absorbs and stores iron. The excess iron gives the skin a bronze color and damages the liver and other organs. Diabetes is also a part of the syndrome due to damage to the pancreas.
Hemoglobin: The oxygen-carrying pigment and predominant protein in the red blood cells. Hemoglobin forms an unstable, reversible bond with oxygen. In its oxygenated state it is called oxyhemoglobin and is bright red. In the reduced state it is called deoxyhemoglobin and is purple-blue. See the entire definition of Hemoglobin
Hemoglobin A: Normal adult hemoglobin, the main type of hemoglobin after infancy. The A stands for Adult.
Heroin: Semisynthetic drug derived from morphine. Discovered in 1874, it was introduced commercially in 1898 by the Bayer company in Germany. The name heroin was coined from the German heroisch meaning heroic, strong. Heroin is stronger (more potent) than morphine.
High blood pressure: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See the entire definition of High blood pressure
HIV: Acronym for the Human Immunodeficiency Virus, the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus. No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase, the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism). See the entire definition of HIV
Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. See the entire definition of Hormone
Hypertension: High blood pressure, defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See the entire definition of Hypertension
Hypertrophy: Enlargement or overgrowth of an organ or part of the body due to the increased size of the constituent cells. Hypertrophy occurs in the biceps and heart because of increased work. Cardiac hypertrophy is recognizable microscopically by the increased size of the cells. The term hypertrophy is applied to the enlargement of the uterus during pregnancy. The term benign prostatic hypertrophy is a misnomer because the increased size of the prostate is due to hyperplasia, an increase in the number of cells.
Hypogonadism: A condition in which decreased production of gonadal hormones leads to below-normal function of the gonads and to retardation of sexual growth and development. (The gonads are the ovaries and testes and the hormones they normally produce include estrogen, progesterone, and testosterone.)
Hypotension: Any blood pressure that is below the normal expected for an individual in a given environment. Hypotension is the opposite of hypertension (abnormally high blood pressure). See the entire definition of Hypotension
Hypothyroid: Deficiency of thyroid hormone which is normally made by the thyroid gland which is located in the front of the neck:
Implant:1. To embed; to set in firmly. In embryology, the fertilized egg implants in the uterine lining 6 or 7 days after conception (fertilization). In medicine today, many things may be implanted. 2. That which is embedded. For example: lens implants, breast implants, cochlear implants, defibrillator implants, pacemaker implants, etc.
Impotence: A common problem among men characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Impotence can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent ability to do so, or a tendency to sustain only very brief erections. See the entire definition of Impotence
Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person. See the entire definition of Infection
Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.
Innervate: To supply with nerves. It is a little known fact that the cornea is the most densely innervated tissue in the body.
Involuntary: Done other than in accordance with the conscious will of the individual. The opposite of voluntary. See the entire definition of Involuntary
Itching: An uncomfortable sensation in the skin that feels as if something is crawling on the skin or in the skin, and makes the person want to scratch the affected area. See the entire definition of Itching
Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.
Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."
LDL cholesterol: Lipoproteins which are combinations of lipids (fats) and proteins are the form in which lipids are transported in the blood. The low-density lipoproteins transport cholesterol from the liver to the tissues of the body. LDL cholesterol is therefore considered the "bad" cholesterol.
Leukemia: Cancer of the blood cells. The growth and development of the blood cells are abnormal. Strictly speaking, leukemia should refer only to cancer of the white blood cells (the leukocytes) but in practice it can apply to malignancy of any cellular element in the blood or bone marrow, as in red cell leukemia (erythroleukemia). See the entire definition of Leukemia
Libido:1. Sexual drive. 2. In psychoanalysis, the psychic energy from all instinctive biological drives. See the entire definition of Libido
Lipid: Another word for "fat." (Please see the various meanings of Fat.) A lipid is more formally defined as a substance such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen and oxygen but have far less oxygen proportionally than carbohydrates. See the entire definition of Lipid
Lipid profile: Pattern of lipids in the blood. (A lipid profile usually includes the total cholesterol, high density lipoprotein (HDL) cholesterol, triglycerides, and the calculated low density lipoprotein (LDL) cholesterol.
Lipids: Another word for "fats." (Please see the various meanings of Fat.) Lipids can be more formally defined as substances such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen and oxygen but have far less oxygen proportionally than carbohydrates. See the entire definition of Lipids
Lithium: Lithium carbonate (brand names: Eskalith; Lithobid), a drug used as a mood stabilizer for the treatment of manic/depressive (bipolar) disorder. It prevents or diminishes the intensity of episodes of mania in bipolar patients. Typical symptoms of mania include pressure of speech, motor hyperactivity, reduced need for sleep, flight of ideas, grandiosity, elation, poor judgment, aggressiveness and possibly hostility. See the entire definition of Lithium
Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.
Liver disease: Liver disease refers to any disorder of the liver. The liver is a large organ in the upper right abdomen that aids in digestion and removes waste products from the blood. See the entire definition of Liver disease
Long QT syndrome: An inherited defect in heart rhythm that predisposes to syncope without warning (sudden fainting spells), dizziness, palpitations, seizures and sudden death. The name of the syndrome comes from the QT segment in the tracing on the electrocardiogram (ECG). This segment lasts slightly longer in the syndrome than normal. The heart takes longer to recharge itself between beats. Certain conditions can trigger an abnormal cardiac rhythm. Among the known triggers are intense physical exercise, swimming, being suddenly startled or badly frightened. See the entire definition of Long QT syndrome
Low blood pressure: Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension. See the entire definition of Low blood pressure
Low testosterone: Abnormally low levels of the male sex hormone testosterone in the blood. Testosterone is produced by the testes and to a lesser extent by the adrenal glands. Testosterone encourages the development of male sexual characteristics at puberty, stimulates the activity of the male secondary sex characteristics, drives the production of sperm, and is involved in regulation of muscle mass and sex drive. Testosterone levels are highly regulated by a complex glandular system. Abnormally low testosterone levels can occur due to a number of conditions affecting the glands that regulate and produce this hormone. Symptoms of low testosterone include decreased libido, impotence or erectile dysfunction, breast enlargement, and a lowered sperm count. Low testosterone levels may be treated with hormone therapy.
Lupus: A chronic inflammatory condition caused by an autoimmune disease. An autoimmune disease occurs when the body's tissues are attacked by its own immune system. Patients with lupus have unusual antibodies in their blood that are targeted against their own body tissues. See the entire definition of Lupus
Luteinizing hormone: A hormone released by the pituitary gland in response to luteinizing hormone- releasing hormone. Abbreviated LH, it controls the length and sequence of the female menstrual cycle, including ovulation, preparation the uterus for implantation of a fertilized egg, and ovarian production of both estrogen and progesterone. In males, it stimulates the testes to produce androgen. Also known as interstitial-cell-stimulating hormone (ICSH).
Marijuana: A very common street and recreational drug that comes from the marijuana plant. See the entire definition of Marijuana
Membrane: A very thin layer of tissue that covers a surface.
Metabolism: The whole range of biochemical processes that occur within an organism. Metabolism consists both of anabolism and catabolism (the buildup and breakdown of substances, respectively). The biochemical reactions are known as metabolic pathways and involve enzymes that transform one substance into another substance, either breaking down a substance or building a new chemical substance. The term is commonly used to refer specifically to the breakdown of food and its transformation into energy.
Mouth:1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.
Multiple myeloma: A malignancy of plasma cells (a form of lymphocyte) that typically involves multiple sites within the bone morrow and secretes all or part of a monoclonal antibody . Also called plasma cell myeloma.
Multiple sclerosis: Abbreviated MS. A disease of the central nervous system (CNS) marked by numbness, weakness, loss of muscle coordination, and problems with vision, speech, and bladder control. MS is an autoimmune disease in which the body's immune system attacks myelin, a key substance that serves as a nerve insulator and helps in the transmission of nerve signals. The progress, severity and specific symptoms in MS are unpredictable. One never knows when attacks will occur, how long they will last, or how severe they will be. Most people with MS are between the ages of 20 and 40 at the time of diagnosis. The term "multiple" refers to the multiple places in the CNS that are affected and to the multiple relapses and remissions characteristic of MS. See the entire definition of Multiple sclerosis
Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."
Myeloma: A tumor of antibody-producing cells, called plasma cells, that are normally found in the bone marrow.
Myopathy: Any and all disease of muscle. Or any type of damage to muscle. There are many different kinds of myopathies. See the entire definition of Myopathy
Nasal: Having to do with the nose. Nasal drops are intended for the nose, not (for example) the eyes. The word "nasal" came from the Latin "nasus" meaning the nose or snout.
Nausea:Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted.
Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.
Neurological: Having to do with the nerves or the nervous system.
Neuropathy: Any and all disease or malfunction of the nerves.
NIH: The National Institutes of Health. The NIH is an important U.S. health agency. It is devoted to medical research. Administratively under the Department of Health and Human Services (HHS), the NIH consists of 20-some separate Institutes and Centers. NIH's program activities are represented by these Institutes and Centers. See the entire definition of NIH
Nitric oxide: A compound that is toxic but which, paradoxically, plays a number of important roles in the body, including the following:
It acts as a vasodilator (blood vessel relaxant).
It therefore controls blood flow to tissues.
It regulates the binding and release of oxygen to hemoglobin.
It thereby controls the supply of oxygen to mitochondria (cell powerhouses that generate energy).
It kills parasitic organisms, virus-infected cells, and tumor cells (by inactivating respiratory chain enzymes in their mitochondria).
Obese: Well above ones normal weight. A person has traditionally been considered to be obese if they are more than 20 percent over their ideal weight. That ideal weight must take into account the person's height, age, sex, and build. See the entire definition of Obese
Obesity: The state of being well above one's normal weight. See the entire definition of Obesity
Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis. There is always an onset to a disease but never to the return to good health. The default setting is good health. See the entire definition of Onset
Opiate: A medication or illegal drug that is either derived from the opium poppy, or that mimics the effect of an opiate (a synthetic opiate). Opiate drugs are narcotic sedatives that depress activity of the central nervous system, reduce pain, and induce sleep. Side effects may include oversedation, nausea, and constipation. Long- term use of opiates can produce addiction, and overuse can cause overdose and potentially death.
Orgasm: The climax of coitus, consisting of a series of involuntary muscle contractions in the anus, lower pelvic muscles, and sexual organs, accompanied by a sudden release of endorphins providing a feeling of euphoria. See the entire definition of Orgasm
Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. See the entire definition of Pain
Pelvic: Having to do with the pelvis, the lower part of the abdomen, located between the hip bones.
Pelvis: The lower part of the abdomen located between the hip bones.
Penile: Of or pertaining to the penis.
Penis: The external male sex organ used to copulate and ejaculate semen and to convey urine outside the body. See the entire definition of Penis
Pituitary:1. As an adjective, pertaining to the pituitary gland or its hormonal secretions. 2. As a noun, the pituitary gland itself. See the entire definition of Pituitary
Placebo: A "sugar pill" or any dummy medication or treatment. See the entire definition of Placebo
Placebo-controlled: A term used to describe a method of research in which an inactive substance (a placebo) is given to one group of participants, while the treatment (usually a drug or vaccine) being tested is given to another group. The results obtained in the two groups are then compared to see if the investigational treatment is more effective than the placebo.
Polycythemia: Too many red blood cells. The opposite of anemia. polycythemia formally exists when the hemoglobin, red blood cell (RBC) count, and total RBC volume are all above normal.
Pregnant: The state of carrying a developing fetus within the body. See the entire definition of Pregnant
Premature ejaculation: Premature ejaculation is ejecting semen from the penis, usually accompanied by orgasm occurring sooner than a man wishes during sexual activity. Premature ejaculation is characterized by a lack of voluntary control over ejaculation that interferes with optimal sexual or psychological well-being in either partner. Also referred to as rapid ejaculation, premature ejaculation typically occurs before or shortly after penetration during sexual intercourse. Premature ejaculation is a common complaint, with an estimated 30% of men regularly suffering from the problem.
Priapism: Abnormally persistent erection of the penis in the absence of sexual desire. Priapism can occur in persons with sickle cell anemia. See the entire definition of Priapism
Prolactin: A hormone secreted by the pituitary gland. Prolactin stimulates lactation (milk production). It also has many other functions, including essential roles in the maintenance of the immune system. See the entire definition of Prolactin
Prospective: Looking forward. A prospective study or a prospective clinical trial is one in which the participants are identified and then followed forward in time.
Prostaglandin: One of a number of hormone-like substances that participate in a wide range of body functions such as the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation. Prostaglandins are derived from a chemical called arachidonic acid.
Prostate: A gland within the male reproductive system that is located just below the bladder. Chestnut shaped, the prostate surrounds the beginning of the urethra, the canal that empties the bladder. See the entire definition of Prostate
Prostate cancer: An uncontrolled (malignant) growth of cells in the prostate gland which is located at the base of the urinary bladder and is responsible for helping control urination as well as forming part of the semen. Prostate cancer is the second leading cause of death of males in the U.S.
Prostate enlargement: Most prostatic enlargement is due to benign prostatic hyperplasia (BPH), a problem that bothers men increasingly with advancing age. The process of BPH generally begins in a man's 30s, evolves very slowly and usually causes symptoms only after he has passed the half-century mark. See the entire definition of Prostate enlargement
Prostate specific antigen: Widely known as PSA. See: PSA.
Prostatectomy: The surgical removal of the prostate gland.
Prostheses: More than one prosthesis. See: Prosthesis.
Protease: An enzyme that can split a protein into peptides (from which the protein was originally created).
Protease inhibitor: One of a class of anti-HIV drugs designed to inhibit the enzyme protease and thereby interfere with virus replication. See the entire definition of Protease inhibitor
PSA: Prostate specific antigen. A test for PSA may be used to screen for cancer of the prostate and to monitor treatment of the disease. See the entire definition of PSA
Psychiatric: Pertaining to or within the purview of psychiatry, the medical specialty concerned with the prevention, diagnosis, and treatment of mental illness. See the entire definition of Psychiatric
Psychogenic: Caused by the mind or emotions.
Psychotherapy: The treatment of a behavior disorder, mental illness, or any other condition by psychological means. Psychotherapy may utilize insight, persuasion, suggestion, reassurance, and instruction so that patients may see themselves and their problems more realistically and have the desire to cope effectively with them. See the entire definition of Psychotherapy
Radiation:1. Rays of energy. Gamma rays and X-rays are two of the types of energy waves often used in medicine. 2. The use of energy waves to diagnose or treat disease. See also: Irradiation.
Randomized: The use of chance alone to assign the participants in an experiment or trial to different groups in order to fairly compare the outcomes with different treatments. Randomization is an important feature of experimental design.
Receptor:1. In cell biology, a structure on the surface of a cell (or inside a cell) that selectively receives and binds a specific substance. There are many receptors. There is a receptor for (insulin; there is a receptor for low-density lipoproteins (LDL); etc. To take an example, the receptor for substance P, a molecule that acts as a messenger for the sensation of pain, is a unique harbor on the cell surface where substance P docks. Without this receptor, substance P cannot dock and cannot deliver its message of pain. Variant forms of nuclear hormone receptors mediate processes such as cholesterolmetabolism and fatty acid production. Some hormone receptors are implicated in diseases such as diabetes and certain types of cancer. A receptor called PXR appears to jump-start the body's response to unfamiliar chemicals and may be involved in drug-drug interactions. 2. In neurology, a terminal of a sensorynerve that receives and responds to stimuli.
Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.
Red blood cell: The blood cell that carries oxygen. Red cells contain hemoglobin and it is the hemoglobin which permits them to transport oxygen (and carbon dioxide). Hemoglobin, aside from being a transport molecule, is a pigment. It gives the cell its red color (and name). See the entire definition of Red blood cell
Referral: The recommendation of a medical or paramedical professional. If you get a referral to ophthalmology, for example, you are being sent to the eye doctor. In HMOs and other managed care schemes, a referral is usually necessary to see any practitioner or specialist other than your primary care physician (PCP), if you want the service to be covered. The referral is obtained from your PCP, who may require a telephone or office consultation first. See the entire definition of Referral
Reservoir:1. A place where something such as water is kept in reserve. 2. The part of a device in which something is kept in reserve or stored, as an Ommaya reservoir. 3. For an infectious agent, an animal, person, plant, soil, or other substance in which the agent normally abides. See: Reservoir of infection. From the French reservoir, from reserver meaning to reserve.
Retinitis pigmentosa: Any one of a large group of inherited disorders in which abnormalities of the photoreceptors (the rods and cones) in the retina lead to progressive visual loss. People with retinitis pigmentosa (RP) first experience defective dark adaptation ("night blindness"), then constriction of the visual field ("tunnel vision") and eventually loss of central vision. See the entire definition of Retinitis pigmentosa
Scleroderma: A disease of connective tissue with the formation of scar tissue (fibrosis) in the skin and sometimes also in other organs of the body. See the entire definition of Scleroderma
Sclerosis: Localized hardening of skin.
Scrotum: A pouch of skin which contains the testes, epididymides, and lower portions of the spermatic cords.
Seizure: Uncontrolled electrical activity in the brain, which may produce a physical convulsion, minor physical signs, thought disturbances, or a combination of symptoms. See the entire definition of Seizure
Sensation: In medicine and physiology, sensation refers to the registration of an incoming (afferent) nerve impulse in that part of the brain called the sensorium, which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.) See the entire definition of Sensation
Sensory: Relating to sensation, to the perception of a stimulus and the voyage made by incoming (afferent) nerve impulses from the sense organs to the nerve centers. See the entire definition of Sensory
Serum: The clear liquid that can be separated from clotted blood. Serum differs from plasma, the liquid portion of normal unclotted blood containing the red and white cells and platelets. It is the clot that makes the difference between serum and plasma. See the entire definition of Serum
Shock: In medicine, shock is a critical condition brought on by a sudden drop in blood flow through the body. There is failure of the circulatory system to maintain adequate blood flow. This sharply curtails the delivery of oxygen and nutrients to vital organs. It also compromises the kidney and so curtails the removal of wastes from the body. Shock can be due to a number of different mechanisms including not enough blood volume (hypovolemic shock) and not enough output of blood by the heart (cardiogenic shock). The signs and symptoms of shock include low blood pressure (hypotension), overbreathing (hyperventilation), a weak rapid pulse, cold clammy grayish-bluish (cyanotic) skin, decreased urine flow (oliguria), and mental changes (a sense of great anxiety and foreboding, confusion and, sometimes, combativeness). See the entire definition of Shock
Sickle cell anemia: A genetic blood disease due to the presence of an abnormal form of hemoglobin, namely hemoglobin S. Hemoglobin is the molecule in red blood cells that transports oxygen from the lungs to the farthest areas of the body. See the entire definition of Sickle cell anemia
Smooth muscle: One of the three types of muscle tissue in the body (skeletal, smooth, cardiac). Generally forms the supporting tissue of blood vessels and hollow internal organs such as the stomach, intestine, and bladder. So named because of the absence of microscopic lines called "cross-striations" which are seen in the other two types.
Spinal cord: The major column of nerve tissue that is connected to the brain and lies within the vertebral canal and from which the spinal nerves emerge. Thirty-one pairs of spinal nerves originate in the spinal cord: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and the brain constitute the central nervous system (CNS). The spinal cord consists of nerve fibers that transmit impulses to and from the brain. Like the brain, the spinal cord is covered by three connective-tissue envelopes called the meninges. The space between the outer and middle envelopes is filled with cerebrospinal fluid (CSF), a clear colorless fluid that cushions the spinal cord against jarring shock. Also known simply as the cord. See the entire definition of Spinal cord
Stage: As regards cancer, the extent of a cancer, especially whether the disease has spread from the original site to other parts of the body. See also: Staging.
Stenosis: A narrowing, as in:
aortic stenosis (narrowing of the aortic valve of the heart),
pulmonary stenosis (narrowing of the pulmonary valve of the heart),
pyloric stenosis (narrowing of the outlet of the stomach), and
spinal stenosis (narrowing of the vertebral canal).
Stethoscope: An instrument used to transmit low-volume sounds such as the heartbeat (or intestinal, venous, or fetal sounds) to the ear of the listener. A stethoscope may consist of two earpieces connected by means of flexible tubing to a diaphragm placed against the skin of the patient. See the entire definition of Stethoscope
Stomach:1. The sac-shaped digestive organ that is located in the upper abdomen, under the ribs. The upper part of the stomach connects to the esophagus, and the lower part leads into the small intestine. See the entire definition of Stomach
Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems. See the entire definition of Stress
Stroke: The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA. See the entire definition of Stroke
Sublingual: Underneath the tongue. A sublingual medication is a type of lozenge put under the tongue where it dissolves and is absorbed. The sublingual gland is a salivary gland under the tongue. See also: Lingual.
Substance:1. Material with particular features, as a pressor substance. 2. The material that makes up an organ or structure. Also known in medicine as the substantia. 3. A psychoactive drug as, for example, in substance abuse.
Substance abuse: The excessive use of a substance, especially alcohol or a drug. (There is no universally accepted definition of substance abuse.) See the entire definition of Substance abuse
Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. See the entire definition of Surgery
Sweating: The act of secreting fluid from the skin by the sweat (sudoriferous) glands. These are small tubular glands situated within and under the skin (in the subcutaneous tissue). They discharge by tiny openings in the surface of the skin. See the entire definition of Sweating
Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease. See the entire definition of Syndrome
Systolic: The blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole. See the entire definition of Systolic
Tachycardia: A rapid heart rate, usually defined as greater than 100 beats per minute. The tachycardias include sinus tachycardia, paroxysmal atrial tachycardia (PAT), and ventricular tachycardia. See the entire definition of Tachycardia
Tactile: Having to do with touch.
Testes: The male sex glands. They are located behind the penis in a pouch of skin called the scrotum. The testes produce and store sperm, and are also the body's main source of male hormones, such as testosterone. These hormones control the development of the reproductive organs and other male characteristics, such as body and facial hair, low voice, and wide shoulders. See the entire definition of Testes
Testicles: The testicles (also called testes or gonads) are the male sex glands. They are located behind the penis in a pouch of skin called the scrotum. The testicles produce and store sperm, and they are also the body's main source of male hormones (testosterone). These hormones control the development of the reproductive organs and other male characteristics, such as body and facial hair, low voice, and wide shoulders.
Testosterone: A "male hormone" -- a sex hormone produced by the testes that encourages the development of male sexual characteristics, stimulates the activity of the male secondary sex characteristics, and prevents changes in them following castration. Chemically, testosterone is 17-beta-hydroxy-4-androstene-3-one. See the entire definition of Testosterone
Testosterone replacement therapy: The practice of giving testosterone to treat conditions in which the testes do not produce enough testosterone. This may be due to absence, injury, or disease. See the entire definition of Testosterone replacement therapy
Therapeutic: Relating to therapeutics, that part of medicine concerned specifically with the treatment of disease. The therapeutic dose of a drug is the amount needed to treat a disease. See the entire definition of Therapeutic
Thyroid:1. The thyroid gland. Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism. 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.) See the entire definition of Thyroid
Topical: Pertaining to a particular surface area. A topical agent is applied to a certain area of the skin and is intended to affect only the area to which it is applied. Whether its effects are indeed limited to that area depends upon whether the agent stays where it is put or is absorbed into the blood stream.
Trauma: Any injury, whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock. This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry, "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects. See the entire definition of Trauma
Treadmill: A machine with a moving strip on which one walks without moving forward. A treadmill was originally a wide wheel turned by the weight of people climbing on steps around its edge, used in the past to provide power for machines or as a punishment in prisons. See the entire definition of Treadmill
Tubes: The "tubes" are medically known as the Fallopian tubes. There are two Fallopian tubes, one on each side, which transport the egg from the ovary to the uterus (the womb). The Fallopian tubes have small hair-like projections called cilia on the cells of the lining. See the entire definition of Tubes
Tunica albuginea: The whitish membrane within the penis that surrounds the spongy chambers (corpora cavernosa) in the penis and which helps to trap the blood in the corpora cavernosa, thereby sustaining erection of the penis. The term comes straight from the Latin tunica (covering or coat) + albuginea (white) = a covering that is white, like the white (albumen) of an egg.
Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy.
Urethra: The transport tube leading from the bladder to discharge urine outside the body. In males, the urethra travels through the penis, and carries semen as well as urine. In females, the urethra is shorter than in the male and emerges above the vaginal opening, as indicated here:
Urinalysis: A test that determines the content of the urine. Because urine removes toxins and excess liquids from the body, it can contain important clues. Urinalysis can be used to detect some types of disease, particularly in the case of metabolic disorders and kidney disease. It can also be used to uncover evidence of drug abuse. See the entire definition of Urinalysis
Urine: Liquid waste. The urine is a clear, transparent fluid. It normally has an amber color. The average amount of urine excreted in 24 hours is from 40 to 60 ounces (about 1,200 cubic centimeters). Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid. Normally, it contains about 960 parts of water to 40 parts of solid matter. Abnormally, it may contain sugar (in diabetes), albumen (a protein) (as in some forms of kidney disease), bile pigments (as in jaundice), or abnormal quantities of one or another of its normal components.
Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system. See the entire definition of Vascular
Ventricular tachycardia: An abnormally rapid heart rhythm that originates from a ventricle, one of the lower chambers of the heart. Although the beat is regular, ventricular tachycardia is life-threatening because it can lead to a dreaded condition, ventricular fibrillation. See the entire definition of Ventricular tachycardia
Zinc: A mineral essential to the body, zinc is a constituent of many enzymes that permit chemical reactions to proceed at normal rates. It is involved in the manufacture of protein (protein synthesis) and in cell division. Zinc is also a constituent of insulin, and is concerned with the sense of smell. See the entire definition of Zinc
Diabetes mellitus is a chronic condition characterized by high levels of sugar (glucose) in the blood. The two types of diabetes are referred to as type 1 (insulin dependent) and type 2 (non-insulin dependent). Symptoms of diabetes include increased urine output, thirst, hunger, and fatigue. Treatment of diabetes depends on the type.
Liver disease can be cause by a variety of things including infection (hepatitis), diseases such as gallstones, high cholesterol or triglycerides, blood flow obstruction to the liver, and toxins (medications and chemicals). Symptoms of liver disease depends upon the cause; however, common symptoms may include nausea, vomiting, upper right abdominal pain, and jaundice. Treatment depends upon the cause of the liver disease.
Low testosterone can affect both men and women. Causes of low testosterone in males include undescended testicles and injury to the scrotum. Low testosterone in females includes ovary conditions. Treatment for low testosterone in men includes testosterone replacement therapy. Currently there is no FDA approved testosterone treatment for women.
Cholesterol is naturally produced by the body, and is a building block for cell membranes and hormones. Low-density lipoprotein (LDL) cholesterol is the "bad" cholesterol, conversely, high-density lipoprotein (HDL) cholesterol is the "good" cholesterol. High cholesterol treatment includes lifestyle changes (diet and exercise), and medications such as statins, bile acid resins, and fibric acid derivatives.
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
Parkinson's disease is a slowly progressive neurologic disease characterized by a fixed inexpressive face, a tremor at rest, slowing of voluntary movements, a gait with short accelerating steps, peculiar posture and muscle weakness, caused by degeneration of an area of the brain called the basal ganglia, and by low production of the neurotransmitter dopamine. Most patients are over 50, but at least 10 percent are under 40.
Testicular pain, or pain in the testicle or testicles are caused by a variety of diseases or conditions such as testicular trauma, testicular torsion, testicular cancer, epididymitis, and orchitis. Common symptoms of pain in the testicle or testicles are abdominal pain, urinary pain or incontinence, fever, nausea, vomiting, and pain in the scrotum or testicle. Treatment depends on the cause of the testicular pain or pain in the testicles.
Drug addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and those around him. Though the initial decision to use drugs is voluntary, changes in the brain caused by repeated drug abuse can affect a person's self-control and ability to make the right decisions and increase the urge to take drugs. Drug abuse and addiction are preventable.
Male sexual dysfunction can be caused by physical or psychological problems. Common sexual problems in men include erectile dysfunction (impotence or ED), premature ejaculation and loss of libido. Treatment for sexual dysfunction in men may involve medication, hormone therapy, psychological therapy, and the use of mechanical aids.
Diabetic Neuropathy is a complication of diabetes that causes damage to the nerves; this is related to the blood glucose of the body being too high for a long period of time. The four types of neuropathy include peripheral, autonomic, proximal and focal.
Smoking is an addiction. More than 430,000 deaths occur each year in the U.S. from smoking related illnesses. Secondhand smoke or "passive smoke" also harm family members, coworkers, and others around smokers. There are a number of techniques available to assist people who want to quit smoking.
Penis disorders (male reproductive problems) include priapism, Peyronie's disease, balanitis, phimosis, paraphimosis, and penile cancer. Read on for causes, symptoms, diagnosis, and treatment. These disorders can affect a man's fertility and sexual functioning. A variety of treatments are available for these disorders.
Prolactinoma is an adenoma (benign tumor) of the pituitary gland. Causes of many prolactinomas are unknown. Symptoms in women include changes in menstruation and infertility, decreased libido, or painful intercourse due to vaginal dryness. The most common symptom in men is impotence (erectile dysfunction). Treatment of prolactinomas are medication or surgery.
Enjoying a satisfying sex life as we age is important to both physical and mental health. As we age, diseases and conditions may pose challenges in our sexual health, and sexual experiences. Learn how to manage your conditions and still have a gratifying sex life as you age.
Anabolic steroids are synthetic substances that are related to testosterone and promote skeletal muscle growth and the development of male sexual characteristics in both men and women. In the 1930s, it was discovered that anabolic steroids could promote skeletal muscle growth in lab animals, which lead to anabolic steroid abuse by bodybuilders and weight lifters.
Sexual health information including birth control, impotence, herpes, sexually transmitted diseases, staying healthy, women's sexual health concerns, and men's sexual health concerns. Learn about the most common sexual conditions affecting men and women.
Peyronie's disease is a condition characterized by a hard lump, or plaque, that forms within the penis. Symptoms of Peyronie's disease range from mild to severe. Treatment for Peyronie's disease includes medication, and often surgery.
Men's health is an important component to a happy lifestyle and healthy relationships. Eating healthy, exercise, managing stress, and knowing when to have medical tests for a particular age is key to disease prevention in men.
Having diabetes can mean early onset and increased severity of bladder symptoms (urinary incontinence and urinary tract infections) and changes in sexual function. Men may have erectile dysfunction; and women may have problems with sexual response and vaginal lubrication. Keep your diabetes under control, and you can lower your risk of sexual and urologic problems.
By smoking, you can cause health problems not only for yourself but also for
those around you.
Hurting Yourself
Smoking is an addiction. Tobacco contains
nicotine, a drug that
is addictive. The nicotine, therefore, makes it very difficult (although not
impossible) to quit. In fact, since the U.S. Surgeon General's 1964 report on
the dangers of smoking, millions of Americans have quit. Still, approximately
440,000 deaths occur in the U.S. each year from smoking-related illnesses; this
represents almost 1 out of every 5 deaths. The
reason for these deaths is that smoking greatly increases the risk of getting
lung cancer, heart attack, chronic lung disease, stroke, and many other cancers.
Moreover, smoking is perhaps the most preventable cause of breathing
(respiratory) diseases within
the USA.
Hurting Others
Smoking harms not just the smoker, but also family
mem...
Sexual Health RSS
Healthy Living Tips
This site complies with the