Some people having chemotherapy treatment find that their mouth gets very sore. Chemotherapy drugs kill cancer cells, but they also harm healthy cells, including cells in the mouth. This can cause side effects such as:

• a sore or dry mouth
• mouth ulcers
• taste changes
• mouth infections.

If mouth problems are more severe, they may affect eating and speaking.

Effects on your mouth depend on which chemotherapy drugs you have and how your body reacts to them. Your cancer doctor or nurse can tell you how your mouth may be affected.

If you have any mouth problems during treatment, always tell your cancer doctor or nurse. They can prescribe treatments and give you helpful advice. Any effects of chemotherapy in the mouth are temporary. They get better when treatment finishes.

Before your treatment begins, a nurse or doctor may examine your mouth and ask about your usual mouth care routine. This is called an oral assessment. It’s done to identify any extra care you need to keep your mouth healthy. They may also give you advice about how to help prevent or reduce mouth problems during treatment.

Before you start your treatment, it is important to see a dentist as soon as possible. Make an appointment for a dental check up and tell your dentist you are going to have chemotherapy. They will help you get your teeth and gums into the healthiest possible condition before your treatment begins. However, it’s not always possible to arrange this in time if you have to start treatment immediately.

If you need to have dental work done during your chemotherapy treatment, it is important to discuss this with your cancer specialist. During chemotherapy, there will be times when you will be at risk of infection and will bleed more easily. This means the timing of any dental work needs to be planned very carefully.

Try to eat a well-balanced diet during your treatment. This will help your mouth to recover from any effects of chemotherapy. Be careful with rough or crunchy foods such as dry toast or crackers, as they can damage the lining of your mouth.

Hot spices, garlic, onion, vinegar and salty foods may irritate your mouth. Acidic drinks, such as orange or grapefruit juice, can also do this. Avoid these if your mouth is sore or more sensitive than usual.

Aim to drink at least one and a half litres (three pints) of fluid a day. This can include water, tea, herbal teas, coffee and soft drinks. It is better to let hot drinks cool a little, so they are warm but don’t scald your mouth.

Smoking irritates your mouth and slows healing. If you do smoke, try to stop or cut down. Your GP can help you with this.

Alcohol also irritates the mouth. Avoid it if:

• your mouth is sore
• your nurse or doctor has told you that you are at high risk of mouth problems during chemotherapy.