Nutritional disorder, with nerve and heart impairment, caused by thiamin deficiency. Its name is from the Sinhalese word for “extreme weakness.” Symptoms include fatigue, digestive problems, and limb numbness and weakness. Dry beriberi involves gradual long-nerve degeneration, with muscle atrophy and loss of reflexes. Wet beriberi is more acute, with edema from cardiac failure and poor circulation. Thiamin occurs widely in food but is lost in processing; a well-balanced diet high in unprocessed foods can prevent beriberi. In Western countries, chronic alcoholism is the most common cause.
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In criminal law, a disease, defect, or condition of the mind that renders one unable to understand the nature of a criminal act or the fact that it is wrong. Tests of insanity are not intended as medical diagnoses but rather only as determinations of whether a person may be held criminally responsible for his or her actions. The most enduring definition of insanity in Anglo-American law was that proposed by Alexander Cockburn (1843). Many U.S. states and several courts have adopted a standard under which the accused must lack “substantial capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of the law.” Some states have abolished the insanity plea, and others allow a finding of “guilty but mentally ill.” Seealso diminished responsibility.
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Most common type of anemia, which may develop in times of high iron loss and depletion of iron stores (e.g., rapid growth, pregnancy, menstruation) or in settings of low dietary iron intake or inefficient iron uptake (e.g., starvation, intestinal parasites, gastrectomy). Much of the world's population is iron-deficient to some degree. Symptoms include low energy level and sometimes paleness, shortness of breath, cold extremities, sore tongue, or dry skin. In advanced cases, red blood cells are small, pale, and low in hemoglobin, blood iron levels are reduced, and body iron stores are depleted. Treatment with iron usually brings quick improvement.
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Inadequate intake or metabolism of iodine. It directly affects thyroid secretions, which influence heart action, nerve response, growth rate, and metabolism. Simple goitre, the most frequent result, is most common in areas without access to salt water and is rare along seacoasts. Severe, prolonged deficiency can cause hypothyroidism. Eating seafood regularly or using iodized table salt will prevent iodine deficiency. Some countries have made dietary iodine additives mandatory.
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Inadequate supply or metabolism of calcium, the main structural element of bones and teeth. Its metabolism is regulated by vitamin D, phosphorus, and hormones (see parathyroid gland). Calcium in the blood has roles in muscle contraction, nerve-impulse transmission, blood clotting, milk production, hormone secretion, and enzyme function, for which calcium is pulled from the bones if deficiency develops. Chronic deficiency may be a factor in the development of osteoporosis or osteomalacia (softening of bone) and may contribute to hypertension and colon cancer. Severe calcium deficiency (hypocalcemia), usually the result of a metabolic problem rather than a dietary deficiency, causes numbness, tingling, and painful muscle aches and spasms.
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Transmissible disease of the immune system caused by HIV. AIDS is the last stage of HIV infection, during which time the individual develops frequently fatal infections and cancers, including Pneumocystis carinii pneumonia, cytomegalovirus (CMV), lymphoma, and Kaposi sarcoma. The first AIDS cases were identified in 1981, HIV was isolated in 1983, and blood tests were developed by 1985. According to the UN's 2004 report on AIDS, some 38 million people are living with HIV, approximately 5 million people become infected annually, and about 3 million people die each year from AIDS. Some 20 million people have died of the disease since 1981. Sub-Saharan Africa accounts for some 70 percent of all HIV infections. Rates of infection are lower in other parts of the world, but the epidemic is spreading rapidly in eastern Europe, India, South and Southeast Asia, Latin America, and the Caribbean.
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