hyperthyroid Having an excessive amount of thyroid hormone resulting from an overactive thyroid gland or from taking too much thyroid hormone. Symptoms of hyperthyroidism can include increased heart rate, weight loss, depression, and cognitive slowing. Treatment can include medications, the use of radioactive iodine, thyroid surgery, or a reduction in the dose of thyroid hormone.
hyperthermia, malignant A rare inherited disease that causes a rapid rise in body temperature and muscle rigidity when a person undergoes general anesthesia. Succinyl choline and halothane are the two drugs most associated with the condition. The result can be destruction of muscle tissue, kidney failure, and death may occur. The propensity to malignant hyperthermia…
hyperthermia Overheating of the body, possibly due to extreme weather conditions. Unrelieved hyperthermia can lead to collapse and death, particularly in the elderly. Hyperthermia can be prevented in many cases through use of air conditioning and ventilation, as well as by ensuring that vulnerable persons drink extra water. In emergency cases of hyperthermia, injections of…
hypertension, pulmonary High blood pressure in the pulmonary arteries. This elevated blood pressure can lead to severe shortness of breath and death. Lung transplantation is considered in severe cases that are unresponsive to treatments.
hypertension, benign intracranial See pseudotumor cerebri.
hypertension See high blood pressure.
hypersomnia Excessive sleepiness in which a person has trouble staying awake during the day or exhibits prolonged nighttime sleep. People who have hypersomnia can fall asleep at any time—for example, at work or while they are driving—and they may have other sleep-related problems. Causes include narcolepsy, sleep deprivation, neurological or other medical conditions, obesity, genetic…
hyperplasia, endometrial A condition characterized by overgrowth of the lining of the uterus. This is considered a precancerous condition.
hyperplasia, benign prostatic See benign prostatic hyperplasia.
hyperplasia An increase in the number of normal cells in a tissue or an organ. Hyperplasia can represent a precancerous condition.
hyperpigmentation Dark spots on the skin. Hyperpigmentation is primarily a cosmetic concern that can be covered with makeup, although in some cases (such as the cafe au lait spots associated with neurofibromatosis) it can be a sign of an underlying medical problem.
hyperphosphatemia An elevated level of phosphate in the blood. Higher-than-normal levels can be caused by ingestion of phosphate-rich foods, such as dairy products, or by kidney failure.