Inappropriate secretion of antidiuretic hormone in Sheehan's syndrome: a rare cause of postpartum hyponatremia.

A 27-year-old woman experienced hemorrhagic shock after delivery. One week later she was seen in an obtunded state of consciousness. The results of laboratory evaluation were consistent with the syndrome of inappropriate antidiuretic hormone secretion caused by hypopituitarism. Hydrocortisone rapidly corrected sodium levels. Syndrome of inappropriate secretion of antidiuretic hormone caused by Sheehan's syndrome should be considered in the differential diagnosis of postpartum hyponatremia.