How chemotherapy can affect your mouth

Chemotherapy can affect the healthy cells in the lining of the mouth. Side effects can include:

  • soreness and ulceration of the mouth
  • mouth infections
  • dry mouth
  • taste changes
  • bleeding gums.

It’s important to see your dentist before you start chemotherapy so they can advise on any dental problems. If you have to start treatment immediately, it’s not always possible to arrange this. If you need dental work during chemotherapy, discuss this with your cancer doctor or nurse.

Keeping your mouth as clean as possible can help reduce side effects. You may have an oral assessment at your hospital and be given advice on how to do this safely. You may also be advised to use certain mouthwashes, protective gels or painkillers to ease any discomfort.

Eating a balanced diet can help your mouth recover after treatment. You may need to avoid certain foods that can irritate the mouth. It will also help not to smoke, and to avoid alcohol if you are at risk of mouth problems.

How chemotherapy affects the mouth

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.


Looking after your mouth

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.


Eating and drinking

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.


Tobacco and alcohol

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.


References and thanks

This page has been compiled using information from a number of reliable sources. If you’d like further information on the sources we use, feel free to contact us.

This information was reviewed by a medical professional. Thank you to all of the people affected by cancer who reviewed what you're reading and have helped our information to develop.

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