Pregnancy, hyperemesis of: Excessive vomiting during pregnancy which, by definition, leads to the loss of 5% or more of the woman's body weight.
Also called hyperemesis gravidarum, the disorder affects one in every 300 pregnant women. It is more common in young women, first pregnancies and women with multiple pregnancies (twins, triplets,)
Hyperemesis of pregnancy is usually self-limited (stops on its own) and, although very inconvenient and very discomforting, is usually of little clinical consequence. However, sometimes hyperemesis can keep the mother from getting the necessary fluids and nutrition.
Some women with hyperemesis of pregnancy have high concentrations of the hormones HCG (human chorionic gonadotropin), estrogen, or thyroid hormone in their blood. A few of them also have clinical manifestations of hyperthyroidism (over-active thyroid state).
The treatment of mild hyperemesis of pregnancy is usually with dietary measures, rest and antacids. Moderate hyperemesis may call for the use of drugs (antiemetics) to try to quell it. Severe hyperemesis gravidarum may require intravenous fluids and, if need be, intravenous nutrition.
"Hyper-", over + "emesis", vomiting = literally, over vomiting or excess vomiting. (Gravidarum refers to the "pregnant state.")