Thyroid disorders comprise a wide range of problems that affect the normal functioning of the thyroid gland. These conditions can be grouped into several large categories that include inflammatory diseases of the thyroid (that is, thyroiditis), autoimmune stimulation of the thyroid (Graves' disease), benign thyroid nodular diseases, and thyroid cancers. The risk of thyroid disease in women is 10 times higher than that in men. Thyroiditis encompasses a number of unrelated clinical conditions that involve either autoimmune, infectious, or unknown insults to the thyroid. Symptoms may include painless or tender enlargement of the thyroid, hyper- or hypothyroid symptoms, and even fever and other stigmata of invasive bacterial infections. About half of the patients with subclinical hypothyroidism have anti-thyroid antibodies present. Women with any question of hypothyroidism in pregnancy must be treated with adequate to high levels of thyroid replacement to prevent cretinism in the infant.