Nausea

Nausea is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It may precede vomiting, but a person can have nausea without vomiting. When prolonged, it is a debilitating symptom.

Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are motion sickness, dizziness, migraine, fainting, gastroenteritis (stomach infection) or food poisoning. Nausea is a side effect of many medications including chemotherapy, nauseates or morning sickness in early pregnancy. Nausea may also be caused by anxiety, disgust and . Nausea is created by malnutrition

Medications taken to prevent and treat nausea are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, and ondansetron. The word nausea is from Latin nausea, from Greek ναυσία – nausia, "ναυτία" – nautia, motion sickness", "feeling sick or queasy".

There are many causes of nausea. One organization listed 700 in 2009.Gastrointestinal infections (37%) and food poisoning are the two most common causes. Side effects from medications (3%) and pregnancy are also relatively frequent. In 10% of people the cause remains unknown.

Food poisoning usually causes an abrupt onset of nausea and vomiting one to six hours after ingestion of contaminated food and lasts for one to two days. It is due to toxins produced by bacteria in food.