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. See the entire definition of Acute
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
Allergic reaction: The hypersensitive response of the immune system of an allergic individual to a substance. See the entire definition of Allergic reaction
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.
Anti-: Prefix generally meaning "against, opposite or opposing, and contrary." In medicine, anti- often connotes "counteracting or effective against" as in antibacterial, anti-infective, and antiviral. Sometimes medical terms containing anti- take on new meanings as has occurred with antibiotic and antibody. As a prefix, anti- may be shortened to ant- as in antacid. "Anti" is the Greek word for "against."
Antidepressants: Anything, and especially a drug, used to prevent or treat depression. See the entire definition of Antidepressants
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
Birth control: Birth control is the use of any practices, methods, or devices to prevent pregnancy from occurring in a sexually active woman. Also referred to as family planning, pregnancy prevention, fertility control, or contraception; birth control methods are designed either to prevent fertilization of an egg or implantation of a fertilized egg in the uterus. See the entire definition of Birth control
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".
Breathing: The process of respiration, during which air is inhaled into the lungs through the mouth or nose due to muscle contraction, and then exhaled due to muscle relaxation.
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. See the entire definition of Caffeine
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
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.
Constipation: Infrequent (and frequently incomplete) bowel movements. The opposite of diarrhea, constipation is commonly caused by irritable bowel syndrome, diverticulosis, and medications (constipation can paradoxically be caused by overuse of laxatives). Colon cancer can narrow the colon and thereby cause constipation. The large bowel (colon) can be visualized by barium enema x-rays, sigmoidoscopy, and colonoscopy. Barring a condition such as cancer, high-fiber diets can frequently relieve the constipation.
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
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
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
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.
Dry skin: Abnormally dry skin. Can be caused by a dry climate, winter weather, deficiency of vitamin A, systemic illness, overexposure to sunlight, or medication. The skin loses moisture. It may crack and peel. Or it may become irritated, inflamed, and itch. Bathing frequently, especially with soaps, can contribute to dry skin. See the entire definition of Dry skin
Enzymes: Proteins that act as a catalysts in mediating and speeding a specific chemical reaction. See the entire definition of Enzymes
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
Flush: (1) A redness of the skin, typically over the cheeks or neck. A flush is usually temporary and brought on by excitement, exercise, fever, or embarrassment. Flushing is an involuntary (uncontrollable) response of the nervous system leading to widening of the capillaries of the involved skin. Also referred to as a blush (or, as a verb, to blush). Flushing may also be caused by medications or other substances that cause widening of the capillaries, such as niacin. (2) Flush also means to wash out a wound or body area.
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.
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
Hair loss: Hair loss is the thinning of hair on the scalp. The medical term for hair loss is alopecia. Alopecia can be temporary or permanent. The most common form of hair loss occurs gradually and is referred to as "androgenetic alopecia," meaning that a combination of hormones (androgens are male hormones) and heredity (genetics) is needed to develop the condition. Other types of hair loss include alopecia areata (patches of baldness that usually grow back), telogen effluvium (rapid shedding after childbirth, fever, or sudden weight loss); and traction alopecia (thinning from tight braids or ponytails). See the entire definition of Hair loss
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 rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate.
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
High blood sugar: An elevated level of the sugar glucose in the blood. Also called hyperglycemia. See the entire definition of High blood sugar
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
Hypothyroid: Deficiency of thyroid hormone which is normally made by the thyroid gland which is located in the front of the neck:
Infarction: The formation of an infarct, an area of tissue death due to a local lack of oxygen. See the entire definition of Infarction
Infertility: The diminished ability or the inability to conceive and have offspring. Infertility is also defined in specific terms as the failure to conceive after a year of regular intercourse without contraception. See the entire definition of Infertility
Insulin: A natural hormone made by the pancreas that controls the level of the sugar glucose in the blood. Insulin permits cells to use glucose for energy. Cells cannot utilize glucose without insulin. See the entire definition of Insulin
Interferon: A naturally occurring substance that interferes with the ability of viruses to reproduce. Interferon also boosts the immune system. See the entire definition of Interferon
Interleukin-2: A type of interleukin, a chemical messenger, a substance that can improve the body's response to disease. It stimulates the growth of certain disease-fighting blood cells in the immune system. Also called IL-2.
Iron: An essential mineral. Iron is necessary for the transport of oxygen (via hemoglobin in red blood cells) and for oxidation by cells (via cytochrome). Deficiency of iron is a common cause of anemia. Food sources of iron include meat, poultry, eggs, vegetables and cereals (especially those fortified with iron). According to the National Academy of Sciences, the Recommended Dietary Allowances of iron are 15 milligrams per day for women and 10 milligrams per day for men. Iron overload can damage the heart, liver, gonads and other organs. Iron overload is a particular risk in people who may have certain genetic conditions (hemochromatosis) sometimes without knowing it and also in people receiving recurrent blood transfusions. Iron supplements meant for adults (such as pregnant women) are a major cause of poisoning in children.
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
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."
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.
Medical history:1. In clinical medicine, the patient's past and present which may contain clues bearing on their health past, present, and future. The medical history, being an account of all medical events and problems a person has experienced, including psychiatric illness, is especially helpful when a differential diagnosis is needed. 2. The history of medicine.
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.
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."
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
Pharmacist: A professional who fills prescriptions, and in the case of a compounding pharmacist, makes them. Pharmacists are familiar with medication ingredients, interactions, cautions, and hints. See the entire definition of Pharmacist
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
Poison: Any substance that can cause severe distress or death if ingested, breathed in, or absorbed through the skin. Many substances that normally cause no problems, including water and most vitamins, can be poisonous if taken in too large of a quantity. Poison treatment depends on the substance: if there are treatment instructions on the substance's container and you are sure it contained no other item, follow those directions immediately. Always contact your nearest Poison Control Center if you are concerned about possible poison ingestion.
Poison Control Center: Special information centers set up to inform Americans about how to respond to potential poisoning. These centers maintain a database of poisons and appropriate emergency treatment. The Poison Control Center in your area should be listed with other community service numbers in the front of your telephone book, and can also be reached immediately through any telephone operator. See the entire definition of Poison Control Center
Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long. See the entire definition of Pregnancy
Pregnant: The state of carrying a developing fetus within the body. See the entire definition of Pregnant
Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container.
Rash: Breaking out (eruption) of the skin. Medically, a rash is referred to as an exanthem.
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
Sensitivity:1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.
Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. See the entire definition of Sodium
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
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.
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
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
Thyroid cancer: Cancer of the gland in front of the neck that normally produces thyroid hormone which is important to the normal regulation of the metabolism of the body. There are 4 major types of thyroid cancer -- papillary, follicular, medullary, and anaplastic. The most common symptom of thyroid cancer is a lump, or nodule, that can be felt in the neck. The only certain way to tell whether a thyroid lump is cancer is by examining the thyroid tissue, obtained using a needle or surgery to obtain a biopsy.
Thyroid gland: A gland that makes and stores hormones that help regulate the heart rate, blood pressure, body temperature, and the rate at which food is converted into energy. Thyroid hormones are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism) in the body. Thyroid hormones also help children grow and develop. See the entire definition of Thyroid gland
Thyroid hormone: A chemical substance made by the thyroid gland for export into the bloodstream. The thyroid gland needs iodine to make thyroid hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). See the entire definition of Thyroid hormone
Thyroid hormones: Chemical substances made by the thyroid gland, which is located in the front of the neck. This gland uses iodine to make thyroid hormones, which are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism), and are involved in the circadian rhythms that govern sleep, among other essential functions. See the entire definition of Thyroid hormones
Tremor: Any abnormal repetitive shaking movement of the body. Tremors have many causes and can be inherited, be related to illnesses such as thyroid disease, or caused by fever, hypothermia, drugs or fear.
Warfarin: An anticoagulant drug (brand names: Coumarin, Panwarfin, Sofarin) taken to prevent the blood from clotting and to treat blood clots and overly thick blood. Warfarin is also used to reduce the risk of clots causing strokes or heart attacks. See the entire definition of Warfarin
Weight loss: Weight loss is a decrease in body weight resulting from either voluntary (diet, exercise) or involuntary (illness) circumstances. Most instances of weight loss arise due to the loss of body fat, but in cases of extreme or severe weight loss, protein and other substances in the body can also be depleted. Examples of involuntary weight loss include the weight loss associated with cancer, malabsorption (such as from chronic diarrheal illnesses ), and chronic inflammation (such as with rheumatoid arthritis).
Hypothyroidism is any state in which thyroid hormone production is below normal. Normally, the
rate of thyroid hormone production is controlled by the brain at the pituitary.
Hypothyroidism is a very common condition and the symptoms of hypothyroidism are
often subtle.
Hypothyroidism
is a condition characterized by abnormally low thyroid
hormone production. There are many disorders that result in
hypothyroidism. These disorders may directly or indirectly involve the thyroid
gland. Because thyroid hormone affects growth, development, and many cellular processes, inadequate thyroid hormone has widespread consequences for the body.
This article will focus specifically on hypothyroidism in adults.
What are thyroid hormones?
Thyroid hormones are produced by the thyroid gland. This gland is located in the lower
part of the neck, below the Adam's apple. The gland wraps around the windpipe
(trachea) and has a shape that is similar to a butterfly - formed by two wings (lobes) and
attached by a middle part (isthmus).
The thyroid gland uses iodine (mostly available from the
diet in foods such as seafood, bread, and salt) to produce thyroid hormones....