Hypothyroidism

Hypothyroidism, or underactive thyroid, occurs when the thyroid gland fails to produce sufficient amounts of the thyroid hormones T4 and T3. The two most common causes of hypothyroidism are radioactive iodine treatment of Graves’ Disease (hyperthyroidism), resulting in a decline or loss of thyroid function; and Hashimoto’s thyroiditis, a common inflammatory condition of the thyroid gland. Less common causes of hypothyroidism include silent (painless or postpartum) thyroiditis and subacute (painful) thyroiditis. In these conditions the hypothyroidism is usually temporary.