Nausea (Latin nausea, from Greek ναυσία – nausia, “ναυτία” – nautia, motion sickness”, “feeling sick or queasy”) is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It occasionally precedes vomiting. A person can suffer nausea without vomiting. (Greek ναῦς – naus, “ship”; ναυσία started as meaning “seasickness”.)
Nausea is a non-specific symptom, which means that it has many possible causes. Some common cause of nausea are motion sickness, dizziness, migraine, fainting, gastroenteritis (stomach infection) or food poisoning. Side effects of many medications including cancer chemotherapy, nauseants or morning sickness in early pregnancy. Nausea may also be caused by anxiety, disgust and depression.