Nausea is the unpleasant urge to vomit. Vomiting is the forceful ejection of stomach contents through the mouth. This is generally a protective mechanism to remove harmful ingested substances, but can occur from many unrelated infectious and inflammatory conditions in the body. Muscles in the abdominal wall contract vigorously to create the pressure necessary for vomiting (retching). Retching, also called ‘dry heaving’ can also occur without vomiting, or can precede or follow vomiting. Similarly, nausea can occur without vomiting or may precede vomiting.
Vomiting must be differentiated from regurgitation, which is the effortless movement of swallowed food contents or stomach acid from the stomach back into the mouth. Regurgitation is not associated with nausea or retching. When regurgitated material tastes sour and bitter, it may be a manifestation of reflux disease, but when it tastes the same as ingested food, it indicates a problem with food movement from the swallowing tube into the stomach. Rumination is another symptom that may resemble vomiting. Rumination consists of regurgitation of ingested food followed by rechewing and reswallowing, and is a learned behavior that may be considered pleasurable by the patient.
Nausea and vomiting are distressing symptoms that can make it difficult to go to work or perform normal activities. Nausea and vomiting after surgery, associated with pregnancy and acute infectious illnesses lead to significant loss of worker productivity and medical expenses. In the United States, it is estimated that the cost of acute stomach infections (often resulting in acute nausea and vomiting) exceeds $1 billion dollars per year in medical expenses alone; the cost of absence from work and lost productivity may be even higher. Some patients feel that nausea and vomiting after surgery is worse than pain after surgery. Nausea and vomiting occurring after a surgical procedure can result in longer hospital stays and higher costs of hospitalization. As many as 8 out of 10 pregnant women develop nausea and vomiting in the early stages of their pregnancy, resulting in time away from work or home. Nausea and vomiting due to cancer chemotherapy can reduce the patient’s ability to complete household tasks, enjoy meals, spend time with others and perform their usual activities.
Common causes of nausea and vomiting include the following:
Nausea is often referred to as a “queasy sensation" or a feeling of being “sick to the stomach.” Nausea may occur with or without vomiting and vomiting can occur without nausea. These symptoms may be accompanied by a sensation of flushing, sweating, salivation, lightheadedness and upper abdominal discomfort. Important associated symptoms include: anorexia, a decreased interest in eating; sitophobia, a fear of eating due to unpleasant symptoms; and early satiety, feeling full early after eating only a small amount of food. Associated symptoms and circumstances prior to the onset of nausea and vomiting can help your doctor determine the cause. The cause of acute nausea and vomiting can very often be diagnosed by doctors just by listening to the patient’s history and performing a physical examination. However, chronic nausea and vomiting, which by definition is when symptoms have lasted longer than 1 month, is more challenging to diagnose and treat.
The cause of an acute episode of nausea and vomiting is typically determined through detailed history and physical examination. Only if the cause remains unclear should further diagnostic tests be performed; sometimes tests are performed to determine if there are harmful consequences from nausea and vomiting. If nausea and vomiting are the result of a minor illness or short-term problem, there may be little cause for concern. However, your doctor will determine if hospital admission is need or if further testing can be performed as an outpatient and if medication may be beneficial. Hospital admission is more common for elderly and the very young, as they can become dehydrated quickly. If diarrhea, dehydration, or both are present, intravenous fluids may be needed, necessitating a visit to the doctor’s office, the emergency room or even admission to the hospital. Finally, even if nausea and vomiting are not particularly severe, hospital admission may be needed for tests and further treatment if symptoms do not improve after several days.
A three step approach is recommended for the evaluation of nausea and vomiting. The first step is to evaluate and treat harmful consequences of nausea and vomiting such as dehydration or alteration in chemical levels in the blood (electrolyte imbalance). Next, the cause of nausea and vomiting is investigated and treated. Finally, if no cause can be determined, therapy to improve symptoms is initiated.
Dehydration and/or imbalance of the body’s electrolytes and minerals circulating in the blood can be problematic when vomiting is severe or prolonged. This is one of the most important acute consequences of nausea and vomiting. Evaluation consists of measuring vital signs (pulse, blood pressure, temperature), physical examination to look for signs of dehydration, checking levels of chemicals in the blood, evaluating kidney and liver function with blood tests and performing limited tests such as an EKG. Treatment consists of intravenous fluids, sometimes with added chemicals (Ringer’s lactate, fluids with added potassium or magnesium).
When symptoms are prolonged, weight loss or malnutrition may occur. Supplementation of nutrition to prevent or to reverse weight loss can include feeding into the intestines (enteral nutrition) or sometimes directly into a large vein (parenteral nutrition).
Forceful retching or vomiting can lead to tears of the intestinal junction, where the esophagus joins with the stomach. When these tears are limited to the inner lining, they are called Mallory-Weiss tears. Mallory-Weiss tears may cause intestinal bleeding. Passing of bright red or dark blood in the vomitus or from the rectum could be due to Mallory-Weiss tears. Rarely, tears can be through the entire wall of the esophagus resulting in perforation and the escape of stomach contents outside the gut, Boerhaave’s syndrome. This is a serious condition and can lead to abscess formation or fluid collection, typically around the bottom of the left lung. Violent retching can occasionally cause painful bruises or tears in the abdominal wall muscles.
After a detailed history and thorough physical examination, your doctor will often be able to determine the cause of nausea and vomiting. Knowing what preceded the onset of nausea and vomiting and the following associated symptoms are important clues to uncovering the diagnosis:
If the diagnosis still remains unclear after a history and physical, the following tests may be used to provide your doctor with more information:
If the cause of nausea and vomiting is not clear after a thorough search and if the symptoms are not controlled with standard therapy, psychological tests and evaluation or psychiatric consultation may prove helpful. Psychogenic vomiting and eating disorders such as anorexia nervosa or bulimia are recognized causes of these symptoms.
The treatment of nausea and vomiting may depend on the cause. However, the following general measures are appropriate for any patient with significant nausea and vomiting.
Episodic nausea and vomiting with a known cause such as motion sickness, chemotherapy, or surgical anesthesia can be prevented with medicines taken just before the causative event or medication. Symptoms due to medications and toxins improve when the drug or toxin is stopped. Morning sickness of pregnancy will usually resolve as the pregnancy progresses or with delivery. Nausea and vomiting due to chronic disorders such as functional problems, psychiatric disorders, endocrine disorders or cancer may be difficult to treat and may need chronic medications to control the symptoms. If nausea and vomiting are related to an infectious or inflammatory condition, symptoms will generally resolve completely with treatment of the primary condition.
Ryan F. Porter, MD, and C. Prakash Gyawali, MD, MRCP, FACG, Washington University, St. Louis, MO – Updated January 2010
Chandra Prakash, MD, MRCP, Washington University, St. Louis, MO – Published June 2005