Nausea is an unpleasant feeling of needing to vomit. People also may feel dizziness, vague discomfort in the abdomen, and an unwillingness to eat.
Vomiting is a forceful contraction of the stomach that propels its contents up the esophagus and out the mouth. (See also Vomiting in Infants and Children.) Vomiting empties the stomach and often makes people with nausea feel considerably better, at least temporarily. Vomiting is quite uncomfortable and can be violent. Severe vomiting can project stomach contents many feet (projectile vomiting).
Vomiting is not the same as regurgitation, which is the spitting up of stomach contents without forceful abdominal contractions or nausea. For instance, people with achalasia or Zenker diverticulum may regurgitate undigested food without nausea.
Vomitus—the material that is vomited up—usually reflects what was recently eaten. Sometimes it contains chunks of food. When blood is vomited, the vomitus is usually red (hematemesis), but if the blood has been partly digested, the vomitus looks like coffee grounds. When bile is present, the vomitus is bitter and yellow-green.
Complications
In addition to being uncomfortable, vomiting can cause complications:
Inhaled vomitus (aspiration)
Torn esophagus (Mallory-Weiss syndrome, esophageal rupture)
Undernutrition and weight loss
People who are unconscious or only partly conscious can inhale their vomitus. The acid in the vomitus can severely irritate the lungs.
Vomiting greatly increases pressure within the esophagus, and severe vomiting can tear the lining of the esophagus (see Mallory-Weiss Syndrome). A small tear causes pain and sometimes bleeding, but a large tear can be fatal.
Because people lose water and minerals (electrolytes) in vomitus, severe vomiting can cause dehydration and electrolyte abnormalities. Newborns and infants are particularly susceptible to these complications.
Chronic vomiting can cause undernutrition, weight loss, and metabolic abnormalities.
Causes of Nausea and Vomiting
Nausea and vomiting result when the vomiting center in the brain is activated. Causes typically involve disorders of the digestive tract or the brain, or ingested substances.
Common causes
The most common causes of nausea and vomiting are
Gastroenteritis (infection of the digestive tract)
Substances (such as medications or illicit drugs)
Toxins
Nausea and vomiting commonly occur with any dysfunction of the digestive tract but are particularly common with gastroenteritis. A less common digestive tract disorder is obstruction of the intestine, which causes vomiting because food and fluids back up into the stomach because of the obstruction. Many other abdominal disorders that cause vomiting also cause significant abdominal pain. In such disorders (for example, appendicitis or pancreatitis), it is typically the pain rather than the vomiting that causes people to seek medical care.
Toxins, such as lead or those found in some foods and plants, can cause severe nausea and vomiting.
Less common causes
Less common causes of nausea and vomiting include
Brain or central nervous system disorders
Motion sickness
Metabolic changes or bodywide (systemic) illness
Psychological disorders
Chronic nausea and vomiting syndrome
Cyclic vomiting syndrome
The vomiting center in the brain also can be activated by certain brain or central nervous system disorders, including infections (such as meningitis and encephalitis), migraines, and disorders that increase pressure inside the skull (intracranial pressure). Disorders that increase intracranial pressure include brain tumors, brain hemorrhage, and severe head injuries.
The balance organs of the inner ear (vestibular apparatus) are connected to the vomiting center. This connection is why some people become nauseated by the movement of a boat, car, or airplane (motion sickness) and by certain disorders of the inner ear (such as labyrinthitis and positional vertigo).
Nausea and vomiting may also occur when there are metabolic changes in the body, such as during early pregnancy, or when people have very poorly controlled diabetes or severe liver failure or kidney failure.
Psychological problems also can cause nausea and vomiting. Such vomiting may be intentional. For instance, people who have bulimia make themselves vomit to lose weight. Or it may be unintentional. For instance, children who are afraid of going to school vomit as a response to their psychological distress.
Chronic nausea and vomiting syndrome is a centrally mediated syndrome or disorder of the gut-brain axis. That is, the nausea and vomiting are not caused by a physical or specific psychological disorder but rather may be a problem with the way the brain and gastrointestinal system communicate. In this syndrome, people have bothersome nausea, vomiting, or both that occur at least once a week for at least 6 months including the last 3 months and that have no identifiable cause after testing has been done.
Cyclic vomiting syndrome is an uncommon disorder in which people have severe attacks of vomiting (or sometimes only nausea) at varying intervals. People feel normal between attacks. Although it usually starts in childhood, it sometimes lasts until adulthood. Cyclic vomiting that begins in adulthood is often due to chronic marijuana (cannabis) use (cannabinoid hyperemesis syndrome). The vomiting can be relieved by a hot shower and goes away after people stop using marijuana.
Evaluation of Nausea and Vomiting
Not every episode of nausea and vomiting requires immediate evaluation by a doctor. The following information can help people decide whether a doctor’s evaluation is needed and help them know what to expect during the evaluation.
Warning signs
Certain symptoms and characteristics are cause for concern. They include
Signs of dehydration (such as thirst, dry mouth, little or no urine output, and feeling weak and tired)
Headache, stiff neck, confusion, or decreased alertness
Constant abdominal pain
Tenderness when the abdomen is touched
Distended (swollen) abdomen
When to see a doctor
People who have warning signs should see a doctor right away, as should people who vomited any blood or who recently had a head injury.
People who have nausea and vomiting but no warning signs should see a doctor if vomiting continues for more than 24 to 48 hours or if they are unable to tolerate more than a few sips of liquid. People who have a few episodes of vomiting (with or without diarrhea) but are able to tolerate at least some liquids should call their doctor. Depending on their age, other symptoms, and known medical conditions (such as cancer or diabetes), the doctor may suggest that people be seen for an evaluation or stay home and try simple remedies.
What the doctor does
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the vomiting and the tests that may need to be done (see table Some Causes and Features of Nausea and Vomiting).
During the history, doctors ask whether the person is pregnant or has diabetes, migraines, liver or kidney disease, or cancer (including the timing of any chemotherapy or radiation therapy). All recently ingested medications and substances are noted because certain substances may not be toxic until several days after ingestion (such as acetaminophen and some mushrooms).
During the physical examination, doctors look for the following:
Signs of dehydration (such as a rapid heart rate, low blood pressure, and dry mouth)
Signs of a serious abdominal disorder (such as a distended abdomen and/or severe tenderness to the touch)
Decreased alertness or any other neurologic abnormalities suggesting a brain disorder
Doctors note any previous abdominal surgery because fibrous bands of scar tissue (adhesions) may have formed and caused an intestinal obstruction.
Although people with previously known disorders that cause vomiting (such as migraine) may simply be having a recurrence of that disorder, doctors thoroughly look for signs of a new, different problem.
Some Causes and Features of Nausea and Vomiting
Cause | Common Features* | Tests† |
|---|---|---|
Digestive tract disorders | ||
Appendicitis or another sudden, severe disorder within the abdomen (such as a perforated intestine, gallbladder inflammation, or pancreatitis) | Significant abdominal pain Abdomen that is tender to the touch | Abdominal imaging tests (such as x-rays, ultrasonography, and/or CT) |
No bowel movements and no flatus Cramping abdominal pain that comes and goes Distended abdomen Usually in people who are known to have a hernia or who have had abdominal surgery | Abdominal x-rays taken with the person in flat and upright positions | |
Vomiting and diarrhea Little or no abdominal pain (except during vomiting) Rarely fever or blood in stool Normal abdominal examination | A doctor’s examination | |
Gastroparesis (poor stomach emptying) | Vomiting of partially digested food a few hours after ingestion Often occurs in diabetics who have elevated blood sugar (glucose) or after abdominal surgery | A doctor’s examination Abdominal x-rays taken when the person is laying down and when upright Nuclear scanning to evaluate stomach emptying in people who may have gastroparesis |
Mild to moderate nausea for many days and sometimes vomiting A general feeling of illness (malaise) Darkening of the urine, then yellowing of the skin and whites of the eyes (jaundice) Loss of appetite Mild discomfort in the upper right part of the abdomen | Blood tests | |
Ileus (temporary absence of the contractile movements of the intestine) | Vomiting and abdominal bloating May occur after surgery, in severe illness, or with severe electrolyte disturbances | X-rays or CT scan |
Ingestion of a toxin (there are many that cause vomiting―common examples include alcohol, aspirin, iron, lead, or insecticides) | Ingestion usually clear based on the person's history Various other symptoms depending on the substance ingested | Depends on the substance ingested but may include blood tests and liver function tests |
Brain and nervous system disorders | ||
Head injury (such as caused by a recent motor vehicle crash, sports injury, or fall) | Injury clear based on the person's history Often headache, confusion, and difficulty remembering recent events | CT of the head |
Sudden, often severe headache Confusion | CT of the head Spinal tap if CT results are normal | |
Brain infection (such as meningitis) | Gradual headache and confusion Often fever and pain with tilting head forward May cause a reddish purple rash of tiny dots on the skin (petechiae) if due to meningococcal meningitis‡ | Spinal tap (sometimes preceded by CT of the head) |
Severe nausea and vomiting with headache and/or dizziness | CT or MRI of the head | |
Cannabis (marijuana) use (cannabinoid hyperemesis syndrome) | Nausea and vomiting (sometimes severe) and sometimes weight loss Usually develops after longstanding cannabis use Relief after a hot shower or goes away after people stop using marijuana | A doctor's examination Urine drug test |
Increased pressure within the skull (such as caused by a blood clot or tumor) | Headache, confusion, and sometimes problems with nerve, spinal cord, or brain function | CT of the head |
Labyrinthitis (inflammation of the inner ear) | A false sensation of movement (vertigo), rhythmic jerking movement of the eyes (nystagmus), and symptoms worsened by motion of the head Sometimes ringing in the ears (tinnitus) | A doctor’s examination Sometimes MRI |
Usually a moderate to severe headache Headache sometimes preceded by seeing flashing lights and blind spots (aura) Sometimes sensitivity to light (photophobia) or temporary disturbances in balance or muscle strength Often a history of repeated similar attacks | A doctor’s examination Sometimes CT or MRI of the head and spinal tap (if results of the examination unclear) | |
Trigger clear based on the person's history of moving, for example, in a boat, car, or airplane | A doctor’s examination | |
Psychological disorders (for example, anorexia nervosa and bulimia nervosa) | No diarrhea or abdominal pain Vomiting that often occurs with stress Repulsed by eating food | A doctor’s examination |
Systemic (bodywide) conditions | ||
An increased volume of urine excreted each day (polyuria), excessive thirst (polydipsia), and often significant dehydration | Blood tests | |
Side effects or toxicity of substances | Ingestion of a medication, illicit drug, or other substance clear based on the person's history | Depends on the substance ingested but may include blood tests |
Often jaundice in advanced liver disease Ammonia odor to the breath in kidney failure Often in people known to have the disorder A crude flapping motion of the hands (asterixis) | Blood and urine tests to evaluate liver and kidney function Blood tests to determine the level of ammonia in the blood | |
Pregnancy | Nausea and/or vomiting often in the morning or triggered by food Normal examination (except the person may be dehydrated) Often a missed or late menstrual period | Pregnancy test† |
Exposure usually clear based on the person's history Severe nausea, vomiting, and diarrhea | A doctor’s examination | |
* Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present. | ||
† Doctors usually do a urine pregnancy test for all girls and women of childbearing age. | ||
‡ Sometimes forceful vomiting (caused by any disorder or condition) causes petechiae on the upper torso and face, which may resemble petechiae caused by meningococcal meningitis, a particularly dangerous form of meningitis. People with meningococcal meningitis are usually very ill, whereas people with petechiae caused by vomiting are often otherwise quite well. | ||
CT = computed tomography; MRI = magnetic resonance imaging. | ||
Testing
The need for tests depends on what doctors find during the history and physical examination, particularly whether warning signs are present and whether findings suggest a particular disorder (see table Some Causes and Features of Nausea and Vomiting).
Possible tests include
Pregnancy test
Blood and urine tests
Girls and women of childbearing age typically should have a pregnancy test.
Otherwise healthy adults and older children who have only a few episodes of vomiting (with or without diarrhea) and no other symptoms typically do not require any testing.
People whose vomiting is severe or has lasted more than 1 day or who have signs of dehydration need laboratory tests of blood (particularly electrolyte levels and sometimes liver tests) and urine.
Treatment of Nausea and Vomiting
Specific conditions are treated.
If there is no serious underlying disorder and the person is not dehydrated, small amounts of clear liquids may be given 30 minutes or so after the last bout of vomiting. Typically 1 or 2 ounces (30 to 50 milliliters) are given at first. Plain water is an appropriate liquid, but broth or weak, sweetened tea may be given. Sports drinks have no particular advantage but are not harmful. If these liquids are tolerated, the amounts are increased gradually. When these increases are tolerated, the person may resume eating normal foods. Carbonated beverages and alcohol should be avoided.
Even when people are slightly dehydrated, doctors usually recommend oral rehydration solutions as long as people can tolerate some liquids by mouth. People with significant dehydration or electrolyte abnormalities, people who are actively vomiting, and people who cannot tolerate any liquids by mouth usually require fluids and sometimes medications given by vein (intravenously).
For some adults and adolescents, doctors give medications to relieve nausea (antiemetics) depending on the cause and the severity of the vomiting:
(See also Treatment of Vomiting in Infants and Children.)
Key Points
People whose nausea and vomiting have an obvious cause and who have a normal examination only need treatment of their symptoms.
People with significant dehydration or electrolyte abnormalities usually require intravenous fluids.
Doctors look for signs of severe, sudden changes to the abdomen or disorders within the skull.
Girls and women of childbearing age are tested for pregnancy.
