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General Information

Nausea and vomiting are serious side effects of cancer therapy.

Nausea and vomiting are very distressing side effects of cancer therapy and affect most patients who have chemotherapy.

Nausea is an unpleasant wavelike feeling in the back of the throat and/or stomach that may lead to vomiting. Vomiting is throwing up the contents of the stomach through the mouth. Retching is the movement of the stomach and esophagus without vomiting and is also called dry heaves. Although treatments have improved, nausea and vomiting are still serious side effects of cancer therapy. Some patients are bothered more by nausea than by vomiting.

Nausea and vomiting must be controlled so that the patient can continue treatment and have a better quality of life.

It is very important to prevent and control nausea and vomiting in patients with cancer, so that they can continue treatment and perform activities of daily life. Nausea and vomiting that are not controlled can cause the following:

  • Chemical changes in the body.
  • Mental changes.
  • Loss of appetite.
  • Malnutrition.
  • Dehydration.
  • A torn esophagus.
  • Broken bones.
  • Reopening of surgical wounds.

There are many types of nausea and vomiting that are caused by cancer therapy:

  • Acute.
  • Delayed.
  • Anticipatory.
  • Breakthrough.
  • Refractory.
  • Chronic.

Acute nausea and vomiting: Nausea and vomiting that happen within 24 hours after beginning chemotherapy.

Delayed nausea and vomiting: Nausea and vomiting that happen more than 24 hours after chemotherapy. Also called late nausea and vomiting.

Anticipatory nausea and vomiting: Nausea and vomiting that happen before a chemotherapy treatment begins. If a patient has had nausea and vomiting after an earlier chemotherapy treatment, he or she may have anticipatory nausea and vomiting before the next treatment. This usually begins after the third or fourth treatment. The smells, sights, and sounds of the treatment room may remind the patient of previous times and may trigger nausea and vomiting before chemotherapy has even begun.

Breakthrough nausea and vomiting: Nausea and vomiting that happen within 5 days after getting antinausea treatment. Different drugs or doses are needed to prevent more nausea and vomiting.

Refractory nausea and vomiting: Nausea and vomiting that does not respond to drugs taken to prevent it.

Chronic nausea and vomiting: In patients with advanced cancer, chronic nausea and vomiting may be caused by radiation therapy. Other causes of chronic nausea and vomiting include the following:

  • Brain tumors or pressure on the brain.
  • Colon tumors.
  • Stomach ulcers.
  • Dehydration.
  • High or low levels of certain substances in the blood.
  • Medicines such as opioids or antidepressants.

Overall healthcare costs are higher for patients with nausea and vomiting that is not controlled.

Healthcare costs for patients with severe nausea and vomiting caused by cancer therapy may be higher due to:

  • Longer hospital stays.
  • Need for help with everyday activities.
  • Lost work hours.
  • Depression.

When nausea and vomiting can be prevented or controlled, healthcare costs are lower. However, even with preventive treatment for nausea and vomiting, many patients may still have uncontrolled symptoms that add to their medical costs and decrease their quality of life.


Chemotherapy is the most common cause of nausea and vomiting in patients being treated for cancer.

Nausea is controlled by a part of the central nervous system that controls involuntary body functions (like the heart beating). Vomiting is a reflex controlled by a vomiting center in the brain. Vomiting can be triggered by smell, taste, anxiety, pain, motion, poor blood flow, irritation, or changes in the body caused by inflammation.

Many factors increase the risk for nausea and vomiting.

Nausea and vomiting are more likely if the patient:

  • Had severe or frequent periods of nausea and vomiting after past chemotherapy treatments.
  • Is female.
  • Is younger than 50 years.
  • Had motion sickness or vomiting with a past pregnancy.
  • Has a fluid and/or electrolyte imbalance (dehydration, too much calcium in the blood, or too much fluid in the body's tissues).
  • Has a tumor in the gastrointestinal tract, liver, or brain.
  • Has constipation.
  • Is receiving certain drugs, such as opioids (pain medicine).
  • Has an infection or blood poisoning.
  • Has kidney disease.

Radiation therapy may also cause nausea and vomiting.

Radiation therapy may cause nausea and vomiting, especially in patients who are receiving radiation therapy to the gastrointestinal tract, liver, or brain. The risk for nausea and vomiting increases as the dose of radiation and the size of the area being treated increase. Nausea and vomiting caused by radiation therapy usually occur one-half hour to several hours after treatment. Patients may have fewer symptoms on days they do not have radiation therapy.

Anticipatory Nausea and Vomiting

Anticipatory nausea and vomiting may occur after several chemotherapy treatments.

Anticipatory nausea and vomiting occur in some patients after they have had several courses of treatment. This is caused by triggers, such as odors in the therapy room. For example, a person who begins chemotherapy and smells an alcohol swab at the same time may later have nausea and vomiting at the smell of alcohol alone. The more chemotherapy sessions a patient has, the more likely it is that anticipatory nausea and vomiting will occur. The following also may make anticipatory nausea and vomiting more likely:

  • Being younger than 50 years.
  • Being female.
  • Having any of the following, after the last chemotherapy session:
    • Nausea and vomiting.
    • Feeling warm or hot.
    • Feeling dizzy or lightheaded.
  • A history of motion sickness.
  • Having a high level of anxiety.
  • Certain types of chemotherapy (some are more likely to cause nausea and vomiting).
  • A history of morning sickness during pregnancy.

The earlier that anticipatory nausea and vomiting is identified, the more effective treatment may be.

Treatment of anticipatory nausea and vomiting is more likely to work when symptoms are treated early. Antinausea drugs given for anticipatory nausea and vomiting do not seem to help. However, the following types of treatment may decrease symptoms:

  • Muscle relaxation with guided imagery.
  • Hypnosis.
  • Behavior changing methods.
  • Biofeedback.
  • Distraction (such as playing video games).

Psychologists and other mental health professionals with special training in these treatments can often help patients with anticipatory nausea and vomiting.

Acute or Delayed Nausea and Vomiting

Acute and delayed nausea and vomiting are common in patients being treated for cancer.

Chemotherapy is the most common cause of nausea and vomiting that is related to cancer treatment.

How often nausea and vomiting occur and how severe they are may be affected by the following:

  • The specific drug.
  • The dose of the drug or if it is given with other drugs.
  • How often the drug is given.
  • The way the drug is given.
  • The individual patient.

The following may make acute or delayed nausea and vomiting with chemotherapy more likely:

  • Having nausea and vomiting after previous chemotherapy sessions.
  • Being female.
  • Being younger than 50 years.
  • Having chemotherapy in the past.
  • A history of motion sickness.
  • A history of morning sickness.
  • Dehydration.
  • Malnutrition.
  • Recent surgery.
  • Radiation therapy.

Patients who have acute nausea and vomiting with chemotherapy are more likely to have delayed nausea and vomiting as well.

Acute and delayed nausea and vomiting are usually treated with drugs.

Acute and delayed nausea and vomiting are usually treated with antinausea drugs. Some types of chemotherapy are more likely to cause acute nausea and vomiting. Drugs may be given before each treatment to prevent nausea and vomiting. After chemotherapy, drugs may be given to prevent delayed vomiting. Some drugs last only a short time in the body and need to be given more often. Others last a long time and are given less often.

The following table shows drugs that are commonly used to treat nausea and vomiting caused by cancer treatment:

Drugs Used to Treat Nausea and Vomiting Caused by Cancer Treatment
Drug Name Type of Drug
Prochlorperazineand otherphenothiazines Phenothiazines
Droperidol,haloperidol Butyrophenones
Metoclopramide Substituted benzamides
Dolasetron,granisetron,ondansetron,palonosetron Serotoninreceptor antagonists
Aprepitant,fosaprepitant,netupitant Substance P/NK-1 antagonists
Dexamethasone,methylprednisolone Corticosteroids
Alprazolam,lorazepam,midazolam Benzodiazepines
Olanzapine Antipsychotic /monoamine antagonists
Marijuana,nabilone Cannabinoids

Treating Nausea and Vomiting Without Drugs

Treatment without drugs is sometimes used to control nausea and vomiting.

Non-drug treatments may help relieve nausea and vomiting, and may help antinausea drugs work better. These treatments include:

  • Nutrition changes (see the Nausea section in the PDQ summary on Nutrition in Cancer Care for more information).
  • Acupuncture and acupressure (see the PDQ summary on Acupuncture for more information).
  • Relaxation methods: Guided imagery and hypnosis are relaxation techniques that have been studied and shown to be helpful in anticipatory nausea and vomiting.
  • Behavior therapy.

Ginger is being studied in the treatment of nausea and vomiting.

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government's center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about the causes and treatment of nausea and vomiting (emesis) (N&V). It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.

The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Supportive and Palliative Care Editorial Board.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

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The best way to cite this PDQ summary is:

PDQ® Supportive and Palliative Care Editorial Board. PDQ Nausea and Vomiting. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: Accessed <MM/DD/YYYY>. [PMID: 26389289]

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Last Revised: 2015-09-02

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