Mouth Sores During Chemotherapy — What Helps

Rinse several times a day and after every meal. Use plain water if nothing else is available. A salt-and-water or bicarbonate-and-water rinse is gentler on inflamed tissue than an alcohol-based mouthwash. The goal is to keep the mouth clean and moist, which supports healing and reduces the risk of infection in broken skin. Ask your team what ratio to use, as recommendations vary.

Cold or room-temperature soft foods cause the least pain. Yoghurt, soft-cooked rice, khichdi, dal without strong spices, curd, ripe banana, and chilled drinks are usually manageable. Avoid anything sharp, crunchy, very hot, spicy, or acidic — these do not cause the sores, but they aggravate them significantly. Small amounts eaten often is easier than three full meals when sores are at their worst.

Most standard pharmacy mouthwashes contain alcohol, which dries and irritates inflamed mouth tissue and can make the sores worse rather than better. They are not suitable during active mouth sores, even if they have always worked well for you before treatment. Ask your team what to use instead — the answer is usually a salt or bicarbonate rinse made at home, which is kinder to damaged tissue.

Yes, and tell your oncology team before any dental work is done, not just your dentist. Chemotherapy affects how the mouth heals and how the immune system responds to infection. Dental procedures during treatment — including routine cleaning — carry a higher risk of complications. Any dental work should be timed around your treatment cycle and cleared with your oncologist first.

Pain that stops you swallowing fluids is the threshold at which your team needs to know the same day. They have options including prescribed pain relief and protective coating gels that can help significantly. Do not try to manage severe pain with over-the-counter medicines alone without asking your team whether that is appropriate. Mild soreness can often be managed with cold foods and frequent rinsing — but know when to call.

Call the same day if you cannot swallow fluids, if you develop a fever alongside the mouth sores, if you notice white patches or a white coating on the tongue or inner cheek that does not rinse away, or if there is bleeding from the mouth that does not stop. These need assessment today, not at your next appointment. Sores that are painful but not stopping you from drinking can usually wait, unless they are getting worse day on day.