Definition A mineral found in the fluid that surrounds cells, magnesium (Mg) is an essential component of more than 300 enzymes that regulate many body functions. Imbalances occur when the blood contains more or less magnesium than it should. Description Magnesium is necessary for the formation and functioning of healthy bones, teeth, muscles, and nerves. It converts food into energy,...

Definition Macular degeneration is the progressive deterioration of a critical region of the retina called the macula. The macula is a 3-5 mm area in the retina that is responsible for central vision. This disorder leads to irreversible loss of central vision, although peripheral vision is retained. In the early stages, vision may be gray, hazy, or distorted. Description Macular degeneration is...

See Lymphadenopathy Masses in the neck are commonly caused by enlargement of the lymph nodes, thyroid gland, or salivary glands. Congenital cysts and benign fatty tumors can also produce local enlargements. Enlargements of the lymph nodes are mentioned in this chapter under Lymphadenopathy. Enlargements of the thyroid gland occur in the various forms of goiter, in thyroiditis, and in cancer of the thyroid...

See also Convulsions: Tremors. A common example of abnormal movements is the tic, a grimace or jerking movement involving just a few muscles. The repetition of a tic is more frequent when a person is under emotional tension. In some cases it occurs only when the individual is ill at ease. A tic often begins as a simple habit spasm in childhood when embarrassment from onlookers compels a movement of some kind....

Inflammatory conditions of the mouth may be caused by several kinds of germs, some producing severe infections; by mechanical injury (cheek biting, poorly fitting dentures or sharp teeth); by local irritants (alcohol, tobacco, hot foods, spices); or by a sensitivity reaction to toothpaste, mouthwashes, or certain drugs. Inflammation of the mouth may appear as a symptom of certain blood diseases: infectious mononucleosis,...

(See Delirium; | Depression This term may refer to difficulties of personal adaptation to an agreeable and accepted way of life. Thus the term includes the neuroses as well as psychotic manifestations (insanity). In a more restricted sense the term refers just to psychoses-illnesses of a disintegrated personality. Their distinguishing characteristic is the patient's inability to distinguish the real from...

Between ages forty-five and fifty a woman passes through a transition period brought about by a decrease in the production of hormones by the ovaries. During this period, menstruation becomes irregular and eventually ceases. Thereafter pregnancy is no longer possible. Many women experience some nervousness during this time A typical sign of the onset of menopause is "hot flashes," when the woman...

A. Normal Menstruation. Menstruation usually lasts two to four days. It is normally accompanied by some aching and intermittent, cramping pain in the lower abdomen. The aching may extend into the lower part of the back. Because of its typical cramping pain, menstruation is commonly called "the cramps." B. Absence of Menstruation (Amenorrhea). The onset of menstruation occurs in a few normal cases...