Nausea and vomiting

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Nausea is feeling sick to your stomach, and vomiting is throwing up. They sometimes occur together. Nausea and vomiting are common side effects of cancer treatment, especially chemotherapy. There are many medicines available to help prevent and control these unpleasant side effects.


Nausea and vomiting in people with cancer can be caused by:

  • chemotherapy
  • radiation therapy
  • targeted therapy
  • other causes

You have a higher chance of having nausea and vomiting if you have more than one type of treatment, such as when chemotherapy is given with radiation therapy.


Chemotherapy may cause the following types of nausea and vomiting:

Acute nausea or vomiting happens in the first 24 hours after chemotherapy is given.

Delayed nausea or vomiting happens more than 24 hours after chemotherapy is given.

Anticipatory nausea or vomiting happens before a chemotherapy treatment is given. If you had nausea or vomiting after a chemotherapy treatment, you may be sick the next time even before having the chemotherapy drugs. This happens because your brain connects certain sights, sounds or smells of the treatment with the nausea or vomiting. These things on their own can then cause nausea and vomiting, even without any chemotherapy drugs being given.

Different chemotherapy drugs have a different likelihood of causing nausea and vomiting. Some drugs are more likely to cause nausea and vomiting when combined with certain other drugs or when given in high doses.

Chemotherapy drugs and combinations of drugs with a higher chance of causing nausea and vomiting include:

  • carmustine (BiCNU)
  • cisplatin
  • cyclophosphamide (Procytox) – when given in high doses
  • dacarbazine
  • daunorubicin (Cerubidine) plus cyclophosphamide
  • doxorubicin plus cyclophosphamide
  • epirubicin plus cyclophosphamide
  • idarubicin plus cyclophosphamide

Radiation therapy

The likelihood that radiation therapy will cause nausea and vomiting depends mostly on the area of the body being treated and the dose of radiation. Higher doses of radiation are more likely to cause nausea or vomiting. Radiation to the whole body (total body irradiation) has a higher chance of causing nausea and vomiting. Radiation to the upper abdomen or to the whole brain and spinal cord (craniospinal radiation) is also likely to cause nausea and vomiting.

Nausea and vomiting usually occur 1 to 3 hours after the radiation treatment.

Targeted therapy

Certain targeted therapy drugs can cause nausea and vomiting. Different targeted therapies have a different likelihood of causing nausea and vomiting. Alemtuzumab (Lemtrada, MabCampath) is the targeted therapy drug that has the highest chance of causing nausea and vomiting.

Other causes

Other causes of nausea and vomiting include:

  • anesthetic given for surgery
  • medicines, especially those given for pain
  • the cancer itself, especially when it affects the brain, liver or gastrointestinal (GI) tract
  • pain
  • high calcium levels (hypercalcemia)
  • low sodium levels (hyponatremia)
  • constipation
  • bowel obstruction
  • infection
  • anxiety


You may have other symptoms with nausea and vomiting. These can vary depending on their cause and other factors. Symptoms that you may have with nausea and vomiting include:

  • gagging or heaving (but not bringing anything up – sometimes called dry heaves)
  • feeling dizzy or light-headed
  • fast heart rate
  • increased saliva
  • paleness
  • sweating
  • feeling weak

Preventing nausea and vomiting

It is important to control nausea and vomiting because your body could lose a lot of fluid and nutrients. This may lead to dehydration, electrolyte imbalances, loss of appetite, malnutrition and a reduced quality of life.

The best way to control nausea and vomiting is to prevent them before they happen. Your healthcare team can prescribe antinausea drugs to prevent or reduce your nausea and vomiting. These drugs are also called anti-emetics.

Prevention is especially important for anticipatory nausea and vomiting. Preventing nausea and vomiting from happening in the first place will stop your brain from connecting your cancer treatment with nausea or vomiting.

Let your healthcare team know if your antinausea drugs are not working. They may change the dose, give you another drug or have you take the drug in a different way.

Antinausea drugs

The antinausea drugs you are given will depend on your cancer treatment. Most often, a combination of drugs is used to treat nausea and vomiting.

Take your antinausea drugs as recommended by your healthcare team. You may be told to take them before your chemotherapy or radiation therapy treatment to help prevent nausea and vomiting. You may also need to take the drugs regularly for several days after treatment. This helps control delayed nausea and vomiting.

Drugs that are most commonly used to prevent and control nausea and vomiting include:

  • aprepitant/fosaprepitant (Emend)
  • dexamethasone
  • granisetron
  • netupitant/palonosetron (Akynzeo)
  • olanzapine (Zyprexa)
  • ondansetron (Ondissolve, Zofran)
  • palonosetron (Aloxi)

Your healthcare team may also prescribe other drugs not listed here.

You can take antinausea drugs in different ways. The most common ways include:

  • injected into a vein
  • swallowed (pill or liquid)
  • dissolved under your tongue (tablet or film)
  • through your skin (patch)

Side effects of antinausea drugs

Antinausea drugs can cause side effects. The side effects depend on the type of drug. Side effects of the commonly used antinausea drugs include:

  • headache
  • dry mouth
  • constipation
  • fatigue
  • feeling sleepy or drowsy
  • feeling dizzy or light-headed
  • increased appetite
  • swelling or puffiness
  • stomach irritation or pain
  • sleep problems
  • mood changes
  • high blood sugar (feeling thirsty, urinating often)

Talk to your healthcare team about any side effects that bother you. Most people feel that the side effects are worth the relief from their nausea and vomiting.

You can find details about specific antinausea drugs from these sources of drug information.

Managing nausea and vomiting

There are many non-drug ways to help manage nausea and vomiting.

Tips for eating and drinking

You can make changes to your eating and drinking habits to see what works for you. For example, some people feel better when they eat before chemotherapy, but some people feel better on an empty stomach. These tips may help you manage nausea and vomiting:

  • Drink small amounts throughout the day.
  • Drink cool or room-temperature beverages rather than cold or hot ones.
  • Avoid alcohol and caffeine.
  • Don’t drink beverages with meals. Drink and eat at least 30 minutes apart.
  • Eat small amounts several times during the day instead of 3 large meals.
  • Don’t let yourself get hungry. Hunger can make nausea worse.
  • Eat bland, easy-to-digest foods that do not upset your stomach, such as plain crackers or toast.
  • Don’t eat foods that have strong smells.
  • Don’t eat foods that are spicy, fatty, sweet or salty.
  • Have someone else prepare and cook food.
  • Eat foods that have helped you with nausea in the past.
  • Eat food cold or at room temperature to avoid smells.
  • Don’t wear clothes that are tight around the waist.
  • Relax and eat slowly.
  • Avoid lying down right after eating.
  • Wait at least 1 hour after your cancer treatment before eating or drinking.

Complementary treatments

Some complementary therapies that may help you manage nausea and vomiting include:

  • acupuncture or acupressure (for acute nausea)
  • guided imagery or visualization (for anticipatory nausea and vomiting)
  • progressive muscle relaxation (for anticipatory nausea and vomiting)
  • hypnosis
  • ginger

Find out more about complementary therapies for people with cancer.


Distracting yourself with music, television, movies or video games may help reduce nausea.

Expert review and references

  • Cindy Murray, RN, BScN, MA
  • American Cancer Society . Nausea and vomiting . 2020 :
  • American Society of Clinical Oncology (ASCO). Nausea and Vomiting.
  • Tipton, J. Nausea and vomiting. Yarbro CH, Wujcik D, Holmes GB, eds.. Cancer Symptom Management . 4th ed. Burlington, MA: Jones and Bartlett Learning; 2014: 213–240.
  • PDQ® Supportive and Palliative Care Editorial Board. Nausea and Vomiting Related to Cancer Treatment (PDQ®) – Health Professional Version. Bethesda, MD: National Cancer Institute; 2020:
  • PDQ® Supportive and Palliative Care Editorial Board. Nausea and Vomiting Related to Cancer Treatment (PDQ®) – Patient Version. Bethesda, MD: National Cancer Institute; 2020:

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