Mouth ulcers are common and should clear up on their own within a week or two. They’re rarely a sign of anything serious but may be uncomfortable to live with. You may have more than one ulcer at a time and they can change in size.

Mouth ulcers aren’t contagious and shouldn’t be confused with cold sores. Cold sores appear on the lips or around the mouth and often begin with a tingling, itching or burning sensation.

If you have several mouth ulcers, this could be a symptom of hand, foot and mouth disease, which also causes a rash on the hands and feet or oral lichen planus, which causes a white, lacy pattern inside the cheeks.


Managing your condition...

Mouth ulcers need time to heal and there is no quick fix. Avoiding things that irritate your mouth ulcer should help speed up the healing process, reduce pain and reduce the change of it returning.



  • use a soft-bristled toothbrush
  • eat very spicy, salty or acidic food
  • drink cool drinks through a straw
  • eat rough, crunchy food, such as toast or crisps
  • eat softer foods
  • drink very hot or acidic drinks, such as fruit juice
  • get regular dental check-ups
  • use chewing gum
  • eat a healthy, balanced diet
  • use toothpaste containing sodium lauryl sulphate


How can I avoid triggers? Suggested lifestyle changes...

You can’t always prevent mouth ulcers. Most single mouth ulcers are caused by things you can try to avoid such as:

  • biting the inside of your cheek
  • badly fitting dentures, braces, rough fillings or a sharp tooth
  • cuts or burns while eating or drinking – for example, hard food or hot drinks
  • a food intolerance or allergy
  • damaging your gums with a toothbrush or irritating toothpaste
  • feeling tired, stressed or anxious

Sometime they’re triggered by things you can’t always control, for example:

  • hormonal changes – such as during pregnancy
  • your genes – some families get mouth ulcers more often
  • a long-term condition – such as inflammatory bowel disease (IBD), coeliac disease or Behçet’s disease
  • a vitamin B12 or iron deficiency
  • medications – including some NSAIDs, beta-blockers or nicorandil
  • stopping smoking – people may develop mouth ulcers when they first stop smoking.


How do I treat?

Speak to your pharmacist who can recommend a treatment to speed up healing, prevent infection or reduce pain, for example:

  • Antimicrobial mouthwash
  • Painkilling mouthwash, gel or spray
  • Corticosteroid lozenges

You can buy these without a prescription but they may not always work.


When should I seek advice?

See a dentist or GP if your mouth ulcer:

  • lasts longer than 3 weeks
  • keeps coming back
  • becomes more painful and red – this may be a sign of an infection
  • Your GP or dentist may prescribe stronger medication to treat severe, recurrent or infected mouth ulcers.

Although most mouth ulcers are harmless, it is best to get long-lasting mouth ulcers checked.