Graves' disease represents a basic defect in the immune system, causing production of immunoglobulins (antibodies) which stimulate and attack the thyroid gland causing growth of the gland and overproduction of thyroid hormone. It is leading cause of hyperthyroidism. Symptoms include hand tremor, weight loss, insomnia, anxiety, restlessness, sensitivity to heat, frequent urination, rapid pulse or irregular heart rhythms. Graves' disease is not curable, but is a completely treatable disease. The more serious complications of prolonged, untreated, or improperly treated Graves' disease include weakened heart muscle leading to heart failure; osteoporosis, or possible severe emotional disorders.
Graves' disease occurs in less that 0.025% of the population. It is more prevalent among females (8:1 more than men) and during middle age, although it also occurs in children and in the elderly.