hookworm An intestinal parasite that infests a billion people, mainly in tropical and subtropical areas. Infection is from contact with soil contaminated by hookworm larvae. First signs are itching and rash at the site where the larvae penetrate the skin. This is followed by diarrhea, intestinal cramps, pain, anorexia, weight loss, and anemia. Loss of…
hormone A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. Many hormones are secreted by special glands, such as thyroid hormone produced by the thyroid gland. Hormones are essential for every activity of life, including the processes of digestion, metabolism, growth, reproduction, and mood control. Many…
hormone, androgenic Any hormone that promotes the development and maintenance of male sex characteristics. Testosterone is an androgenic hormone.
hormone, follicle-stimulating See folliclestimulating hormone.
hormone, mineralocorticoid A group of hormones, the most important of which is aldosterone, that regulates the balance of water and electrolytes (ions such as sodium and potassium) in the body. The mineralocorticoid hormones act specifically on the tubules of the kidney. See also corticosteroid.
hormone, thyroid A chemical substance that is made by the thyroid gland, which is located in the front of the neck. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). Thyroid hormones are critical for regulation of the body’s metabolism. See also thyroxine; triiodothyronine.
hormone, thyroid-stimulating See thyroidstimulating hormone.
hormone, thyrotropin See thyroid-stimulating hormone.
hormone replacement therapy The use of medications containing both estrogen and progestogen to reduce or stop short-term changes associated with the perimenopause, such as hot flashes, disturbed sleep, and vaginal dryness. Abbreviated HRT. Many physicians now use the term hormone therapy, abbreviated HT, rather than HRT. HRT can ease the symptoms of menopause and protect…
hormone therapy Treatment of disease or symptoms with synthetic or naturally derived hormones. The term is most commonly used to describe use of medications containing both estrogen and progestogen to reduce or stop short-term changes associated with the perimenopause. In the more general sense, hormone therapy may be used to treat some forms of cancer,…
Horner ptosis See Horner syndrome.
history See history, medical.