Nausea is a feeling of queasiness in the stomach. It is usually associated with the feeling that one is going to throw up, or vomit.
What is going on in the body?
Nausea is a feeling that almost everyone has had at some point in their lives. It can be caused by many different conditions, ranging from pregnancy or exercising too much to infection or cancer. Determining the cause of nausea is not always easy.
What are the signs and symptoms of the condition?
Most people with nausea have some of the following symptoms as well: There may be other symptoms, too, depending on the cause of the nausea.
What are the causes and risks of the condition?
The list of conditions that can cause nausea is very long. It is best broken down into general categories. These include:
Other causes are possible. In some cases, no cause can be found.
- an infection in the digestive tract, such as food poisoning
- an infection in another part of the body, such as the flu or an ear infection known as acute otitis media
- gastro-oesophageal reflux
- peptic ulcers
- problems with balance and equilibrium, such as motion sickness
- anxiety and other psychological conditions
- certain drugs, such as antibiotics, narcotics, cancer chemotherapy, oral contraceptives, and analgesias
- problems in the abdomen, such as appendicitis, gallbladder disease, gallstones, kidney stones, hepatitis, pancreatitis, or bowel inflammation
- a blockage in the stomach, bowels, or oesophagus, the tube that connects the mouth to the stomach. Oesophageal atresia is an example of this type of blockage.
- system-wide conditions, such as poorly controlled diabetes, headaches, cancer, chronic renal failure, heart attacks, being overly tired, overexerting oneself, and hormone or salt imbalances
- birth defects in the digestive tract, such as a poorly formed stomach or intestine. These may include duodenal atresia, pyloric stenosis or imperforate anus.
What can be done to prevent the condition?
Prevention is related to the underlying cause. For example, avoiding alcohol can prevent nausea from drinking too much. Medications can help with the nausea caused by travelling. If the nausea is due to morning sickness during pregnancy, eating crackers and avoiding fatty foods can help. There are many other examples of prevention depending on the specific cause.
How is the condition diagnosed?
People can diagnose nausea on their own. A doctor can help a person figure out the cause of the nausea. The first step is a history and physical examination. In some cases, this may be all that is needed to diagnose the cause. In other cases, many other tests may be needed. Blood, urine, and x-ray tests are commonly done.
What are the long-term effects of the condition?
Nausea itself has no serious long-term effects, though it may be distressing and prevent sleep and other activities. The underlying cause may be very serious, however. For example, cancer is a rare cause of nausea that can lead to death. If vomiting occurs with the nausea, dehydration and salt imbalances may occur.
What are the risks to others?
Nausea itself is not contagious and poses no risk to others. In some cases, nausea is due to an infection that may be contagious.
What are the treatments for the condition?
Treatment is directed at the underlying cause. For example, if the cause is gastro-oesophageal reflux, medications can be given to treat the reflux. If the cause is appendicitis, surgery is needed to remove the appendix. Medications are also available to treat nausea if the cause cannot be treated or avoided. For example, people who need chemotherapy to treat cancer are often given drugs to reduce nausea before chemotherapy begins.
Some drugs that may help reduce nausea are available over-the-counter, such as diphenhydramine. Others are more powerful, such as ondansetron or dronabinol, and require a prescription.
What are the side effects of the treatments?
All medications have possible side effects. For example, diphenhydramine makes many people sleepy. Other drugs can cause allergic reactions, diarrhoea, or other side effects. Specific side effects depend on the medications used. Any surgery carries a risk of bleeding, infection, and reactions to analgesics.
What happens after treatment for the condition?
If the underlying cause can be found and treated, the nausea should stop. If the cause cannot be found or cannot be treated, drugs to reduce nausea may help. For example, some people may need narcotics to control pain, but the narcotics make them nauseous. In this case, drugs to treat nausea can be given at the same time as the analgesias.
How is the condition monitored?
People with nausea can monitor it themselves as well as how it responds to treatment. The underlying cause of nausea may need further monitoring and treatment.
Author: Adam Brochert, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request