Hyperthyroidism appearing as hyperemesis gravidarum

Vomiting is a poorly recognized manifestation of hyperthyroidism. During pregnancy, this appearance can be indistinguishable from hyperemesis gravidarum. Two patients with intractable hyperemesis gravidarum were found to have hyperthyroidism. Their symptoms resolved when thyroid functions returned to normal. Given the ease of laboratory confirmation, excellent therapy, and the seriousness of delay in diagnosis, thyrotoxicosis should be considered in patients with unusual or severe hyperemesis gravidarum.