Nausea is the sensation of having to vomit or having the urge to vomit. Vomiting may or may not occur as a result of nausea. Some describe the sensation of nausea as unsettled feeling in the stomach or queasiness. It is not a disease but a symptom of a variety of conditions, ranging from viral and bacterial infections to motion sickness, to food poisoning, to abscesses of the brain. Certain medications can cause nausea.
