Hyperemesis graviarum (from Greek hyper and emesis and Latin gravida; meaning "excessive vomiting of pregnant women") is a severe form of morning sickness, with unrelenting, excessive pregnancy-related nausea and/or vomiting that prevents adequate intake of food and fluids. Hyperemesis is considered a rare complication of pregnancy but, because nausea and vomiting during pregnancy exist on a continuum, there is often not a good diagnosis between common morning sickness and hyperemesis. Estimates of the percentage of pregnant women afflicted range from 0.3% to 2%.