Emesis (vomiting or throwing up) is the act of expelling the contents of the stomach through the mouth. Nausea is the urge to vomit. Radiation therapy  (the use of high-energy x-rays or other particles to kill cancer cells) and some types of chemotherapy  (the use of drugs to kill cancer cells) cause nausea and vomiting , although not all patients who receive these treatments will have these side effects. Patients who often have motion sickness or have vomited after previous chemotherapy treatment are more likely to experience nausea and vomiting.
The best way to manage nausea and vomiting caused by cancer treatment is to prevent it. Fortunately, many medications are available that can prevent vomiting. These medications may also prevent nausea, but some patients may still have nausea even if they do not have vomiting. More research is needed to understand if these drugs prevent nausea.
Anticipatory emesis is vomiting that occurs before treatment in patients who have previously felt nauseous or vomited after chemotherapy. The prevention and treatment of anticipatory vomiting depends on the patient. Tell your doctor if you have experienced vomiting with previous chemotherapy treatment. Your doctor may be able to recommend medication or behavioral therapy to help reduce vomiting.