General Information

Nausea and vomiting are serious side effects of cancer therapy.

Nausea and vomiting are side effects of cancer therapy and affect most patients who have chemotherapy. Radiation therapy to the brain, gastrointestinal tract, or liver also cause nausea and vomiting.

Nausea is an unpleasant feeling in the back of the throat and/or stomach that may come and go in waves. It may occur before 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 for nausea and vomiting have improved, nausea and vomiting are still serious side effects of cancer therapy because they cause the patient distress and may cause other health problems. Patients may have nausea more than vomiting.

Nausea is controlled by a part of the autonomic nervous system which controls involuntary body functions (such as breathing or digestion). Vomiting is a reflex controlled in part by a vomiting center in the brain. Vomiting can be triggered by smell, taste, anxiety, pain, motion, or changes in the body caused by inflammation, poor blood flow, or irritation to the stomach.

It is important that nausea and vomiting are 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.

Different types of nausea and vomiting are caused by chemotherapy, radiation therapy, and other conditions.

Nausea and vomiting can occur before, during, or after treatment.

The types of nausea and vomiting include:

• Acute: Nausea and vomiting that happen within 24 hours after treatment starts.
• Delayed: Nausea and vomiting that happen more than 24 hours after chemotherapy. This is also called late nausea and vomiting.
• Anticipatory: Nausea and vomiting that happen before a chemotherapy treatment begins. If a patient has had nausea and vomiting after an earlier chemotherapy session, 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 the chemotherapy session has even begun.
• Breakthrough: 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 that does not respond to drugs.
• Chronic: Nausea and vomiting that lasts for a period of time after treatment ends.

Causes

Many factors increase the risk of nausea and vomiting with chemotherapy.

Nausea and vomiting with chemotherapy are more likely if the patient:

• Is treated with certain chemotherapy drugs.
• Had severe or frequent periods of nausea and vomiting after past chemotherapy treatments.
• Is female.
• Is younger than 50 years.
• Had morning 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, including an infection in the blood.
• Has kidney disease.

Patients who drank large amounts of alcohol over time have a lower risk of nausea and vomiting after being treated with chemotherapy.

Radiation therapy may also cause nausea and vomiting.

The following treatment factors may affect the risk of nausea and vomiting:

• The part of the body where the radiation therapy is given. Radiation therapy to the gastrointestinal tract, liver, or brain, or whole body is likely to cause nausea and vomiting.
• The size of the area being treated.
• The dose of radiation.
• Receiving chemotherapy and radiation therapy at the same time.

The following patient factors may cause nausea and vomiting with radiation therapy if the patient:

• Is younger than 55 years.
• Is female.
• Has anxiety.
• Had severe or frequent periods of nausea and vomiting after past chemotherapy or radiation therapy treatments.

Patients who drank large amounts of alcohol over time have a lower risk of nausea and vomiting after being treated with radiation therapy.

Other conditions may also increase the risk of nausea and vomiting in patients with advanced cancer.

Nausea and vomiting may also be caused by other conditions. In patients with advanced cancer, chronic nausea and vomiting may be caused by the following:

• Brain tumors or pressure on the brain.
• Tumors of the gastrointestinal tract.
• High or low levels of certain substances in the blood.
• Medicines such as opioids.

Anticipatory Nausea and Vomiting

Anticipatory nausea and vomiting may occur after several chemotherapy treatments.

In some patients, after they have had several courses of treatment, nausea and vomiting may occur before a treatment session. This is called anticipatory nausea and vomiting. It 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 an alcohol swab. The more chemotherapy sessions a patient has, the more likely it is that anticipatory nausea and vomiting will occur.

Having three or more of the following may make anticipatory nausea and vomiting more likely:

• Having nausea and vomiting, or feeling warm or hot after the last chemotherapy session.
• Being younger than 50 years.
• Being female.
• A history of motion sickness.
• Having a high level of anxiety in certain situations.

Other factors that may make anticipatory nausea and vomiting more likely include:

• Expecting to have nausea and vomiting before a chemotherapy treatment begins.
• Doses and types of chemotherapy (some are more likely to cause nausea and vomiting).
• Feeling dizzy or lightheaded after chemotherapy.
• How often chemotherapy is followed by nausea.
• Having delayed nausea and vomiting after chemotherapy.
• A history of morning sickness during pregnancy.

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

When symptoms of anticipatory nausea and vomiting are diagnosed early, treatment is more likely to work.

Psychologists and other mental health professionals with special training can often help patients with anticipatory nausea and vomiting. The following types of treatment may be used:

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

Antinausea drugs given for anticipatory nausea and vomiting do not seem to help.

Acute or Delayed Nausea and Vomiting

Acute and delayed nausea and vomiting are common in patients being treated with chemotherapy.

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 being given.
• 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 if the patient:

• Had chemotherapy in the past.
• Had nausea and vomiting after previous chemotherapy sessions.
• Is dehydrated.
• Is malnourished.
• Had recent surgery.
• Received radiation therapy.
• Is female.
• Is younger than 50 years.
• Has a history of motion sickness.
• Has a history of morning sickness during pregnancy.

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 with chemotherapy or radiation therapy are usually treated with drugs.

Drugs may be given before each treatment, to prevent nausea and vomiting. After chemotherapy, drugs may be given to prevent delayed vomiting. Patients who are given chemotherapy several days in a row may need treatment for both acute and delayed nausea and 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 prevent nausea and vomiting caused by chemotherapy and the type of drug.

The following table shows drugs that are commonly used to prevent nausea and vomiting caused by radiation therapy and the type of drug:

It is not known whether it is best to give antinausea medicine for the first 5 days of radiation treatment or for the full treatment course. Talk with your doctor about the treatment plan that is best for you.

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:

• Diet 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 such as guided imagery and hypnosis.
• Behavior therapy.

Treatment-Related Nausea and Vomiting in Children

Nausea and vomiting in children treated with chemotherapy is a serious problem.

Like adults, nausea in children receiving chemotherapy is more of a problem than vomiting. Children may have anticipatory, acute, and/or delayed nausea and vomiting.

Anticipatory nausea and vomiting may occur in children.

Children who have nausea and vomiting after a chemotherapy treatment may have the same symptoms before their next treatment when the child sees, smells, or hears sounds from the treatment room. This is called anticipatory nausea and vomiting.

When the child’s nausea and vomiting is well controlled during and after a chemotherapy treatment, the child may have less anxiety before the next treatment and less chance of having anticipatory symptoms.

Health professionals caring for children who have anticipatory nausea and vomiting have found that children may benefit from:

• Hypnosis.
• Drugs used to treat anxiety in doses adjusted for the age and needs of the child.

In children, acute nausea and vomiting is usually treated with drugs and other methods.

Drugs may be given before each treatment to prevent nausea and vomiting. After chemotherapy, drugs may be given to prevent delayed vomiting. Patients who are given chemotherapy several days in a row may need treatment for both acute and delayed nausea and 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 prevent nausea and vomiting caused by chemotherapy and the type of drug. Different types of drugs may be given together to treat acute and delayed nausea and vomiting.

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

• Acupuncture.
• Acupressure.
• Guided imagery.
• Music therapy.
• Muscle relaxation training.
• Child and family support groups.
• Virtual reality games.

Dietary support may include:

• Eating smaller meals more often.
• Avoiding food smells and other strong odors.
• Avoiding foods that are spicy, fatty, or highly salted.
• Eating “comfort foods” that have helped prevent nausea in the past.
• Taking antinausea drugs before meals.

Delayed nausea may be hard to detect in children.

Unlike in adults, delayed nausea and vomiting in children may be harder for parents and caregivers to see. A change in the child’s eating pattern may be the only sign of a problem. In addition, most chemotherapy treatments for children are scheduled over several days. This makes the timing and risk of delayed nausea unclear.

Studies on the prevention of delayed nausea and vomiting in children are limited. Children are usually treated the same way as adults, with doses of drugs that prevent nausea adjusted for age.

About This PDQ Summary

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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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PDQ® Supportive and Palliative Care Editorial Board. PDQ Nausea and Vomiting Related to Cancer Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/about-cancer/treatment/side-effects/nausea/nausea-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389289]

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Last Revised: 2018-09-21

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