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Mucositis is when your mouth or gut is sore and inflamed. It's a common side effect of chemotherapy and radiotherapy for cancer.

Although mucositis is usually painful, it can be treated. It should get better within a few weeks of finishing cancer treatment.

If you're having treatment that may cause mucositis, there are some things you can do to help prevent or ease it.


  • brush your teeth with a soft toothbrush at least twice a day

  • gently floss once a day if you can

  • rinse your mouth with warm water (or water mixed with a bit of salt) several times a day

  • suck on crushed ice or ice lollies

  • eat soft, moist foods, like soup, jelly or soft fruit, or try adding gravy or sauces to meals

  • drink plenty of water

  • chew sugar-free gum (this can help keep your mouth moist)

  • use a moisturiser or balm to stop your lips getting dry

  • leave out dentures if you wear them, and keep them clean and moist even when you're not wearing them


  • do not use mouthwashes from shops without speaking to a pharmacist, nurse or doctor – they might irritate your mouth

  • do not take painkillers without speaking to a pharmacist, nurse or doctor

  • do not eat crunchy, rough or sharp foods like crisps

  • do not eat spicy or acidic foods, as these can cause irritation

  • do not eat hot foods, as these can also irritate your mouth – try eating your meals warm or cool

  • do not drink fizzy drinks or alcohol

  • do not smoke

Non-urgent advice: Tell your care team if you're having cancer treatment and get:

  • a sore mouth
  • mouth ulcers
  • difficulty swallowing, eating or talking
  • a dry mouth and lips
  • diarrhoea, bleeding from your bottom, or pain when pooing

These are symptoms of mucositis. They usually begin around 1 to 2 weeks after starting cancer treatment.

Your care team can offer treatments to ease it, such as:

  • mouthwashes that clean, numb and protect your mouth
  • painkillers
  • sprays or gels to keep your mouth moist (saliva substitutes)
  • medicines to stop diarrhoea or reduce soreness inside your bottom (rectum)

Talking to others can help

You may find it helps to chat to people in a similar situation or who have had cancer treatment.

Ask your care team about support groups in your area.

You could also try an online forum like: