Good oral care is important during cancer treatment. Some anticancer drugs can cause sores in the mouth and throat, a condition called stomatitis or mucositis. Anticancer drugs also can make these tissues dry and irritated or cause them to bleed. Patients who have not been eating well since beginning chemotherapy are more likely to get mouth sores. In addition to being painful, mouth sores can become infected by the many germs that live in the mouth. Every step should be taken to prevent infections, because they can be hard to fight during chemotherapy and can lead to serious problems. 
