ChemotherapyChemotherapy is one of the most helpful therapies available to cancer patients, but it is also often the most damaging. As the radiated chemicals kill off the cancer cells, they kill off some of the healthy cells as well. Patients undergoing chemotherapy therefore experience a number of severely debilitating side effects as well, including nausea, weakness, fatigue, soreness in the mouth, throat, and gums, and many more. For such patients, marijuana may be helpful for restoring appetite and reducing pain and discomfort.