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Nausea and Vomiting (PDQ®)

NCI PDQ Summaries for Patients

General Information
Anticipatory Nausea and Vomiting
Acute or Delayed Nausea and Vomiting
Treating Nausea and Vomiting Without Drugs
Changes to This Summary (09/02/2015)
About This PDQ Summary
Questions or Comments About This Summary
Get More Information From NCI

Nausea & VomitingNausea and Vomiting

General Information

Nausea and vomiting are serious side effects of cancer therapy.

Nausea and vomiting are very distressing side effects of cancertherapy 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:

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

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:

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:

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:

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 TreatmentDrug NameType of DrugProchlorperazine and other phenothiazinesPhenothiazinesDroperidol, haloperidolButyrophenonesMetoclopramideSubstituted benzamidesDolasetron, granisetron, ondansetron, palonosetronSerotonin receptor antagonistsAprepitant, fosaprepitant, netupitantSubstance P/NK-1 antagonistsDexamethasone, methylprednisoloneCorticosteroidsAlprazolam, lorazepam, midazolamBenzodiazepinesOlanzapineAntipsychotic/monoamine antagonistsMarijuana, nabiloneCannabinoids

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:

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

Changes to This Summary (09/02/2015)

The PDQcancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Changes were made to this summary to match those made to the health professional version.

About This PDQ Summary

About PDQ

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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.

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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.

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Date last modified: 2015-09-02