Nausea and Vomiting in Adults

We have selected the following expert medical opinion based on its clarity, reliability and accuracy. Credit: Sourced from the MSD Manual, Consumer Version; authored by Dr Norton J. Greenberger (see below). Please refer to your own medical practitioner for a final perspective, assessment or evaluation.

Overview

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 oesophagus and out the mouth. 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 oesophagus (Mallory-Weiss tear)
• Dehydration and electrolyte abnormalities
• 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 oesophagus, and severe vomiting can tear the lining of the oesophagus. 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

Nausea and vomiting result when the vomiting centre 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)
• 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.

Many drugs, including alcohol, opioid analgesics (such as morphine), and chemotherapy drugs, can cause nausea and vomiting. 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
• Psychologic disorders
• Cyclic vomiting syndrome

The vomiting centre 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 tumours, brain haemorrhage, and severe head injuries.

The balance organs of the inner ear (vestibular apparatus) are connected to the vomiting centre. This connection is why some people become nauseated by the movement of a boat, car, or airplane 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 diabetes that is severely out of control or severe liver failure or kidney failure.

Psychologic problems also can cause nausea and vomiting (known as functional or psychogenic 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 psychologic distress.

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 use.

Evaluation

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 diarrhoea) 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 section: 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 drugs 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

Please note: Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present.

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

Intestinal obstruction

• No bowel movements and no flatus (passing of air)
• 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

Gastroenteritis

• Vomiting and diarrhoea
• Little or no abdominal pain (except during vomiting)
• Rarely fever or blood in stool
• Normal abdominal examination

Hepatitis

• 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

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

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

Brain haemorrhage

• Sudden, often severe headache
• Confusion

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‡
• Increased pressure within the skull (such as caused by a blood clot or tumour)
• Headache, confusion, and sometimes problems with nerve, spinal cord, or brain function

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)

Migraine

• 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

Motion sickness

• Trigger clear based on the person's history

Psychologic disorders

• No diarrhoea or abdominal pain
• Vomiting that often occurs with stress
• Consumption of food considered repulsive

Systemic (bodywide) conditions

Diabetic ketoacidosis

• An increased volume of urine excreted each day (polyuria), excessive thirst (polydipsia), and often significant dehydration
• Drug side effects or toxicity
• Ingestion of a drug or substance clear based on the person's history

Liver failure or kidney failure

• Often jaundice in advanced liver disease
• Ammonia odour to the breath in kidney failure
• Often in people known to have the disorder

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

Radiation exposure

• Exposure usually clear based on the person's history
• Severe nausea, vomiting, and diarrhoea

Tests and special investigations

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 section: 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 diarrhoea) 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

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, 30 millilitres (an ounce) or two 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. Carbonated beverages and alcohol should be avoided. If these liquids are tolerated, the amounts are increased gradually. When these increases are tolerated, the person may resume eating normal foods.

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/or drugs given by vein (intravenously).

For some adults and adolescents, doctors give drugs to relieve nausea (antiemetics) depending on the cause and the severity of the vomiting:

• For vomiting caused by motion sickness: Antihistamines (such as dimenhydrinate), scopolamine patches, or both
• For mild to moderate symptoms: Prochlorperazine or metoclopramide
• For severe vomiting (including vomiting caused by chemotherapy): Dolasetron, ondansetron, or granisetron, or sometimes aprepitant

KEY POINTS

• People whose nausea and vomiting have an obvious cause and who have a normal examination only need treatment of their symptoms.
• 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.

About the author

Dr Norton J. Greenberger

MD

Clinical Professor of Medicine, Harvard Medical School; Senior Physician, Brigham and Women's Hospital

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