Nausea and vomiting during pregnancy.

The differential diagnosis of nausea and vomiting is extensive and the underlying cause can be difficult to diagnose. Treatment of nausea and vomiting also can be unsatisfactory because the available pharmacotherapy does not correct the fundamental underlying pathophysiologic abnormalities. In contrast, the diagnosis of nausea and vomiting of pregnancy generally is straightforward. Almost 80% of women have some degree of nausea in the first trimester of pregnancy, and the diagnosis of pregnancy is established easily by the patient or physician. The spectrum varies from mild nausea to hyperemesis gravidarum. Various treatment approaches are addressed.