Many people with cancer experience nausea (an urge to vomit, or throw up) and vomiting. Mild nausea and vomiting can be quite uncomfortable, but usually causes no serious problems. Persistent vomiting can cause dehydration, electrolyte imbalance (loss of minerals in the body, such as potassium and sodium),weight loss, depression, and result in a person stopping treatment.

Causes

Nausea and vomiting in people with cancer may be caused by the following:

• Chemotherapy
  
  
• Radiation therapy, especially to the brain, spinal cord, abdomen, and pelvis. People who have received total body radiation therapy (such as before a bone marrow transplantation) are at the highest risk.
  
  
• Cancer that has spread to the brain
  
  
• Blocked intestines (bowel obstruction)
  
  
• Electrolyte imbalance
  
  
• Infections or bleeding in the gastrointestinal (stomach and intestines) system
  
  
• Heart disease
  
  
• Other medications

Anticipatory vomiting occurs in people who have previously vomited after receiving chemotherapy. It can happen in the time before a person knows he or she must go back to the hospital to have more chemotherapy. Acute vomiting is vomiting that takes place in the first 24 hours after treatment. Delayed vomiting may continue two or more days after treatment.

People who are at the highest risk for chemotherapy-induced nausea and vomiting include the following:

• People who have previously vomited after cancer treatment
  
  
• People who are prone to motion sickness
  
  
• People who are anxious before cancer treatment
  
  
• People under age 50, especially women

Preventing and managing nausea and vomiting

Whenever possible, it is best to prevent nausea and vomiting from starting. Many medications are available to help reduce or stop vomiting. If you are at risk for nausea and vomiting, your doctor may prescribe antiemetic medications (drugs to stop vomiting) before cancer treatment. In addition, many people find that behavioral treatments can help control nausea and vomiting. Methods such as distraction, relaxation, and positive imagery can help change the expectation and fear of nausea and vomiting. In some situations, the doctor may be able to recommend another treatment plan that is less likely to cause vomiting.

More Information

ASCO's Guideline on Preventing Nausea and Vomiting Caused by Cancer Treatment.

Nutrition Recommendations During and After Treatment

Additional Resources

American Cancer Society: Nausea and Vomiting

Livestrong: How to Prevent Vomiting

Last Updated: September 25, 2009