Common causes of hypothyroidism?

*hashimotos thyroidistis - most common (autoimmune disease of the thyroid) *Previous treatment for hyperthyroidism ie: Loss of thyroid tissue - thyroidectomy, radioiodine treatment, anti thyroid medication Iodine deficiency *Drug induced hypothyroidism such as from Lithium *Congenital Hypothyroidism (Guthrie Test) can retard growth and mental development