What are the risk factors for oral mucositis?

Oral mucositis is inflammation and ulceration of the mouth lining. Cancer treatment can injure cells that normally replace this delicate lining. Chemotherapy can affect the mouth throughout the body, while radiotherapy can cause irritation in the area being treated, especially when the mouth or throat is within the treatment field.

Risk can also be influenced by dry mouth, gum disease, broken teeth, dentures that rub, smoking, alcohol use, dehydration, and difficulty maintaining oral hygiene. A history of mouth sores or nutritional problems may add to vulnerability. A risk factor does not mean sores will definitely develop.

Arrange a dental review before treatment when possible, so damaged teeth, gum problems, or rubbing dentures can be addressed safely. Use a soft toothbrush, rinse gently as advised, drink regularly, and choose soft foods if chewing hurts. Avoid tobacco, alcohol-containing mouthwashes, and foods that are sharp, very hot, spicy, or acidic.

Tell the oncology team before treatment starts if you already have mouth ulcers, dental pain, dry mouth, or trouble eating. Treatment plans can sometimes include preventive mouth care and tailored pain or nutrition support. Learn about [Radiotherapy](/treatments/radiation-oncology/radiotherapy/) and [Chemotherapy](/treatments/systemic-therapy/chemotherapy/).

Contact your treatment team promptly if mouth pain prevents drinking, ulcers are worsening, you cannot swallow medicines, or you develop fever. Seek urgent help for breathing difficulty, swelling that rapidly increases, confusion, or signs of severe dehydration such as very little urine and dizziness.

Is my treatment likely to irritate the mouth? Should I see a dentist before treatment? Which mouth rinse is suitable for me? What pain relief is safe? Who should I call if eating or drinking becomes difficult?