Nausea and vomiting are symptoms of an underlying disease and not a specific illness. Nausea is the sensation that the stomach wants to empty itself, while vomiting (emesis) or throwing up, is the act of forcible emptying of the stomach.
Vomiting is a violent act in which the stomach has to overcome the pressures that are normally in place to keep food and secretions within the stomach.
The stomach almost turns itself inside out - forcing itself into the lower portion of the esophagus (the tube that connects the mouth to the stomach) during a vomiting episode.
There are numerous causes of nausea and vomiting.
These symptoms may be due to the following:
- acute gastritis;
- central causes (signals from the brain);
- association with other illnesses remote from the stomach;
- medications and medical treatments;
- mechanical obstruction of the bowel.
Acute gastritis (gastro=stomach + it is= inflammation) is often caused by an offending agent which irritates the lining of the stomach.
Examples of these include:
- Infections: Infections are often the cause, whether it is a common virus or an infection that is contracted from travel. There may be associated crampy upper abdominal pain, fever ,and chills may be present. Common viral infections include noroviruses and rotavirus. Parasitic infections often are associated with diarrhea but may also have a component of nausea and vomiting. Infection by bacteria in the Helicobacter family (like H. Pylori) can also be the infectious agent.
- Stomach flu: Stomach flu is a non-specific term used to describe vomiting and diarrhea associated with a viral infection. It should not be confused with influenza, whose symptoms include fever, chills, cough, and myalgias (muscle pain).
- Food poisoning: Food poisoning may cause significant vomiting and usually is caused by a bacterial toxin. Symptoms begin within a couple hours of eating contaminated or poorly prepared food and may last for 1-2 days. Sources of food poisoning include Salmonella, Campylobacter, Shigella, E.coli, Listeria, or Clostridium botulinum (botulism).
- Other stomach irritants: alcohol, smoking, and non steroidal anti-inflammatory medications such as aspirin and ibuprofen may irritate the stomach lining.
- Peptic ulcer disease: Peptic ulcer disease can range from mild irritation of the stomach lining to the formation of a defect in the protective lining of the stomach called an ulcer.
- Gastroesophageal reflux disease (GERD, reflux esophagitis): Nausea or vomiting is also associated with irritation of the lining of the esophagus
Symptomatic treatment may occur while the underlying illness is being investigated because ideally, nausea and vomiting should resolve when the cause of the symptoms resolves.
Nausea and vomiting are often made worse when the patient is dehydrated, resulting in a vicious cycle. The nausea makes it difficult to drink fluid, making the dehydration worse, which then increases the nausea. Intravenous fluids may be provided to correct this issue.
There are a variety of anti-nausea medications (antiemetics) that may be prescribed. They can be administered in different ways depending upon the patient's ability to take them. Medications are available by pill, liquid, or tablets that dissolve on or under the tongue, by intravenous or intramuscular injection, or by rectal suppository.
Common medications used to control nausea and vomiting includepromethazine (Phenergan), prochlorperazine (Compazine), droperidol (Inapsine) metoclopramide (Reglan), and ondansetron (Zofran). The decision as to which medication to use will depend on the specific situation.