When are mouth problems from cancer treatment serious?

Mouth problems from cancer treatment are more serious when they interfere with eating and drinking. That can lead to dehydration and malnutrition.

Call your doctor or nurse if you have pain in your mouth, lips, or throat that makes it difficult to eat, drink, or sleep. Call as well for a fever of 100.4–100.5 degrees F (38 degrees C) or higher. That range is a little fuzzy because sources word the threshold differently, so use the number your own team gave you.

These problems happen because some treatments can harm the mouth, throat, and lips. Radiation therapy to the head and neck, some chemotherapy, and some immunotherapy can all do this. Problems may include taste changes, dry mouth, infections, and mouth sores. You may also have pain or swelling (oral mucositis), sensitivity to hot or cold foods, swallowing problems, and tooth decay. Checking and cleaning your mouth daily can help prevent problems, and so can a dental check-up before treatment. There are also ways to manage a sore or dry mouth. Your healthcare team can tell you which symptoms to call about, and what steps and medicines may help.