hyperthyroidism /-thī″roidiz′əm/ [Gk, hyper + thyreos, shield, eidos, form] , a condition characterized by hyperactivity of the thyroid gland. The gland is usually enlarged, secreting greater than normal amounts of thyroid hormones, and the metabolic processes of the body are accelerated. Nervousness, exophthalmos, tremor, constant hunger, weight loss, fatigue, heat intolerance, palpitations, and diarrhea may develop. Antithyroid drugs, such as propylthiouracil or methimazole, are usually prescribed. Radioactive iodine may be prescribed in certain cases. Surgical ablation of the gland is sometimes necessary. Untreated hyperthyroidism may lead to death from cardiac failure. See also Graves’ disease, thyroid storm.
