A condition in which the thyroid gland makes too many thyroid hormones.

Hyperthyroidism can be caused by various health conditions that affect the thyroid. The thyroid is a gland in the neck that makes important hormones. These hormones control the process by which the body turns food and drink into energy. Hyperthyroidism speeds up this process. Another name for the condition is overactive thyroid.

Hyperthyroidism can cause many different symptoms. A person may have unexplained weight loss and more hunger. The hands and fingers may tremble. The heartbeat may feel fast, out of rhythm or pounding. The menstrual cycle may change. Anxiety or irritation may increase. A person also might sweat more or become sensitive to heat.

Hyperthyroidism treatment includes medicines that can keep the thyroid from making too many hormones. Less often, surgery is needed to remove part or all of the thyroid. Treatment depends on factors such as age, overall health and the cause of hyperthyroidism. Sometimes the condition may get better without treatment, depending on the cause.