Morning sickness is nausea that occurs during pregnancy. The name is a misnomer, however, since morning sickness can strike at any time of the day or night.
Morning sickness affects a large proportion of pregnant women. It is most common during the first trimester, but for some women morning sickness lingers throughout pregnancy. Treatment isn't usually needed — although various home remedies, such as snacking throughout the day and sipping ginger ale, often help relieve nausea.
Rarely, morning sickness is so severe that it's classified as hyperemesis gravidarum. This type of morning sickness may require hospitalization and treatment with intravenous (IV) fluids and medications.