Patients with this syndrome usually have no prior history of thyroid disease. Mild hyperthyroidism is noted one to three months after an uncomplicated delivery and is followed by a brief euthyroid period. Symptomatic hypothyroidism develops three to six months postpartum. The syndrome is self-limited. The hypothyroidism is treated in the usual manner with levothyroxine. This syndrome may be confused with postpartum depression.