Vomiting is the body’s way of removing harmful or irritating substances from the gut. It is a symptom of an underlying issue, rather than a condition in itself.

There are many potential causes of vomiting. Some are relatively benign and may clear up without the need for medical treatment. Others are more serious and require immediate medical attention.

In this article, we outline what vomiting is, the conditions that cause it, and what to do after vomiting. We also provide tips on how to prevent some of the illnesses that can trigger vomiting, and look at when a person should contact a doctor.

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Vomiting is a forceful contraction of the stomach that propels the stomach contents up through the esophagus, or food pipe, and out of the mouth.

Vomiting occurs following activation of the “vomiting center,” an area within the brain where the brain detects toxins and can signal vomiting as a result.

In some cases, a person may experience projectile vomiting. This is where the stomach contracts violently, projecting its contents over a distance of a few feet.

Vomiting is uncomfortable, but it typically causes feelings of nausea to temporarily or permanently subside.

There are various steps a person can take after vomiting to help them feel better. These include:

  • Staying hydrated: If a person is having difficulty keeping liquids down, they should regularly sip small amounts of water to avoid dehydration.
  • Slowly reintroducing bland foods: A person who is experiencing nausea or vomiting should stick to eating bland, easy-to-digest foods, such as:
  • Avoiding foods that could trigger nausea and vomiting: Examples of foods to avoid include:
    • fatty or greasy foods
    • spicy foods
    • sugary foods
  • Avoiding strong odors: Strong odors can trigger nausea and vomiting, so a person should try to stay away from any strong-smelling foods or substances.
  • Eating smaller meals more often: Rather than eating three large meals per day, a person should aim to eat smaller meals more frequently throughout the day. This approach will be easier on the digestive system.

Below, we list some potential causes of vomiting.

Infections of the digestive tract

Nausea and vomiting are often due to an infection of the digestive tract.

One of the most common causes of nausea and vomiting in both adults and children is the gut infection gastroenteritis. The infection may be bacterial or viral in nature and usually clears up within 1 week.

Additional symptoms of gastroenteritis may include:

Intestinal obstruction

A less common cause of vomiting is intestinal obstruction. This is where an obstruction within the intestines causes food or fluid to back up into the stomach.

Other possible signs of intestinal obstruction include:

Pancreatitis

The pancreas is a small organ that helps with digestion, and regulation of blood sugar levels.

Pancreatitis is the medical term for inflammation of the pancreas. This can occur as a result of the following:

  • gallstones
  • excessive alcohol consumption
  • a viral infection
  • accidental damage or injury to the pancreas
  • a side effect of certain medications

Besides vomiting, some symptoms of pancreatitis include:

Appendicitis

The appendix is a small pouch that connects to the large intestine. It sits in the lower right abdomen. Experts are still unsure as to its function.

Appendicitis is the medical term for painful inflammation of the appendix. Doctors do not know what causes the condition, though it may be due to a blockage at the entrance of the appendix.

Symptoms of appendicitis may include:

  • nausea and vomiting
  • loss of appetite
  • constipation or diarrhea
  • high temperature and a flushed complexion

Taking medication or ingesting toxins

Drugs that can cause nausea and vomiting include:

People may also experience severe nausea and vomiting following exposure to a toxin, or ingestion of a poison.

Anyone who is concerned that they may have ingested a poison should call the AAPCC helpline or 911 for expert advice.

Conditions of the brain or central nervous system

Certain brain or central nervous system conditions may activate the vomiting center. Examples include:

Motion sickness

The inner ear contains special organs called the vestibular system, which plays an important role in balance and spatial coordination.

The vestibular system is connected to the vomiting center of the brain. When a person is traveling by car, boat, or train, the signals coming from their vestibular system are different from those they are receiving through their eyes. This causes some people to become nauseated and vomit.

Other possible symptoms of motion sickness include:

Disorders of the inner ear

Certain disorders of the inner ear may also cause nausea and vomiting. Examples include:

  • Benign paroxysmal positional vertigo (BPPV): This is a condition in which some of the calcium carbonate crystals migrate from one part of the inner ear to another. With BPPV, any movement or change in position could trigger an episode of vertigo.
  • Labyrinthitis: This is infection and inflammation of the labyrinth, a network of fluid-filled channels inside the inner ear.
  • Ménière’s disease: This condition affects the inner ear and may be due to pressure disturbances deep inside the ear.

Metabolic changes

Changes to a person’s metabolism can cause them to feel nauseated and vomit.

Metabolic changes and associated vomiting can be a result of:

Mental health conditions

Some mental health conditions can increase the likelihood of vomiting. Examples include:

  • Bulimia nervosa: This is an eating disorder in which a person intentionally induces vomiting.
  • Anxiety: Anxiety is a feeling of intense worry or fear that can cause a cascade of physical symptoms, including nausea and vomiting.

Cyclic vomiting syndrome

Cyclic vomiting syndrome (CVS) is a rare condition that causes a person to have severe attacks of vomiting at varying intervals. The disorder usually starts during childhood and can persist into adulthood.

CVS that begins in adulthood is often the result of chronic marijuana use.

It is not always possible to prevent vomiting. However, the following tips may help reduce the likelihood of vomiting occurring.

Practicing good hygiene

A person can reduce their likelihood of developing viral and bacterial infections that may induce vomiting, by practicing good hygiene. This includes:

  • washing the hands frequently
  • storing food at the correct temperature
  • washing counter tops, cutting boards, and knives before food preparation
  • using different cutting boards for fruit and vegetables, meat, and fish
  • washing the hands after touching raw poultry, fish, and other meat
  • using a meat thermometer to ensure meat is cooked to a safe temperature
  • rinsing fruit and vegetables thoroughly before eating

Taking antinausea medications

Antiemetics are medications that can help treat nausea and vomiting.

Some antiemetics work by speeding up the movement of food through the gut, while others work by blocking signals to the vomiting center in the brain.

Some common antiemetics include:

  • Hyoscine: This medication blocks a chemical in the brain called acetylcholine. It is an especially effective treatment for nausea caused by motion sickness or inner ear problems.
  • Cinnarizine, cyclizine, and promethazine: These drugs belong to a group of medications called antihistamines. Experts believe antihistamines work by blocking histamine H1 receptors in the area of the brain that causes nausea in response to chemicals in the body. These medicines are effective for various types of nausea.
  • Metoclopramide: This medicine works directly on the gut. It eases feelings of sickness by speeding up digestion. Doctors often prescribe it for people with migraine or sickness due to gut problems.
  • Granisetron, ondansetron, and palonosetron: These medications block the chemical serotonin in the gut and brain. Serotonin has an action in the gut and brain that can cause nausea. These medications are especially useful for treating nausea and vomiting resulting from chemotherapy.
  • Certain antipsychotic medications: The brain chemical dopamine can activate the vomiting center of the brain. Certain antipsychotic medications can block dopamine in the brain. They are effective against nausea that is due to:

Sometimes, vomiting can indicate a serious underlying health problem. A person should seek guidance from a doctor if they experience the following symptoms:

Also, vomiting can sometimes indicate a serious underlying health condition that requires urgent treatment.

A person should seek emergency medical attention if they experience any of the following:

  • sudden and severe abdominal pain
  • severe chest pain
  • sudden, severe headache unlike any they have had before
  • high temperature and a stiff neck
  • vomit containing blood or a substance that resembles coffee grounds
  • possible ingestion of a poison or other toxic substance

Vomiting is a forceful contraction of the stomach that projects the stomach contents up through the food pipe and out of the mouth. It occurs in response to the activation of the vomiting center in the brain.

There are many possible causes of vomiting. Some are relatively benign and transient, while others may signal a serious underlying health issue that requires urgent treatment.

If a person is concerned about vomiting or other symptoms, they should contact a doctor for a diagnosis and appropriate treatment. Anyone who experiences severe or debilitating symptoms should seek emergency medical attention.

After vomiting, a person should eat frequent, small, bland meals. They should also drink plenty of fluids to restore adequate hydration.