Nausea is the term used to describe the feeling a patient has in their stomach that they want to vomit. It is rare in patients who have not recently eaten. It is a common symptom of many conditions and as such is not very useful in a differential diagnosis. However, if nausea persists after vomiting, it usually indicates a serious condition.
Some common conditions that cause nausea are:
- Poisoning, including food poisoning.
- Infections of the inner ear.
- Exposure to general anesthesia, such as ether or nitrous oxide.
- Exposure to certain toxic gases, such as natural gas.
- Chemotherapy, where it is the most common side effect.
- An imbalance of blood chemistry, often typical of patients with diabetes.
- Viral diseases such as influenza.
Simple nausea can usually be treated by allowing the patient to vomit and keeping them away from food. However, where it persists, and the patient cannot hold down liquids, intravenous fluids are usually necessary until the underlying cause is found.