Hyperthyroidism

Hyperthyroidism is a condition in which the thyroid gland produces excess thyroid hormone, accelerating the body's metabolism and affecting the heart, bones, muscles, and nervous system. The prevalence of hyperthyroidism in the United States is approximately 1.2%, with overt hyperthyroidism accounting for 0.5% and subclinical hyperthyroidism — where lab values are abnormal but symptoms may be absent — accounting for 0.7%. Hyperthyroidism is significantly more prevalent in women than men (2% vs. 0.2%), and NHANES data show that thyrotoxicosis is nearly three times more common in non-Hispanic Black individuals than in White individuals. The most common cause is Graves' disease, an autoimmune condition in which the immune system overstimulates the thyroid; other causes include toxic multinodular goiter and thyroid adenomas. Symptoms can include rapid heartbeat, unintended weight loss, anxiety, tremors, and heat sensitivity. Onset most commonly occurs between ages 20 and 50, though the condition is more prevalent overall in adults over 60. Treatment options include antithyroid medications, radioactive iodine therapy, and surgery, with the goal of restoring normal hormone levels and preventing cardiovascular and bone-related complications.