Thyrotoxicosis in the very old.

The records of 25 patients older than 75 years of age with the diagnosis of hyperthyroidism were reviewed. The mean age of the group (22 women and three men) was 81.5 years, the eldest being 95 years old. Twenty-one patients had Graves' disease, three had multinodular goiter, and one had toxic adenoma. Major presenting symptoms included weight loss (44 percent), palpitations (36 percent), and weakness (32 percent). The average number of thyrotoxic symptoms was only two per patient. Two patients were asymptomatic. Clinical signs included fine skin (40 percent), tremor (36 percent), atrial fibrillation (32 percent), and tachycardia (28 percent). The thyroid was palpable in only three patients with Graves' disease. Mean blood thyroxine level was 15.6 micrograms/dl (range, 11.5 to 24); blood triiodothyronine level was elevated in only half of the patients. One patient had triiodothyronine toxicosis. Mean 24-hour radioiodine uptake was 52 percent. Five patients had normal uptake. No correlation could be established between age, clinical symptoms, signs, and hormone blood levels. Because signs and symptoms of hyperthyroidism in the very old may be too subtle for clinical diagnosis, all elderly subjects should have periodic screening of blood thyroxine levels.