Mouth ulcers are common and should clear up on their own within a week or 2. They're rarely a sign of anything serious, but may be uncomfortable to live with.
Mouth ulcers need time to heal and there's no quick fix.
Avoiding things that irritate your mouth ulcer should help:
- speed up the healing process
- reduce pain
- reduce the chance of it returning
use a soft-bristled toothbrush
drink cool drinks through a straw
eat softer foods
get regular dental check-ups
eat a healthy, balanced diet
do not eat very spicy, salty or acidic food
do not eat rough, crunchy food, such as toast or crisps
do not drink very hot or acidic drinks, such as fruit juice
do not use chewing gum
do not use toothpaste containing sodium lauryl sulphate
A pharmacist can recommend a treatment to speed up healing, prevent infection or reduce pain, such as:
- antimicrobial mouthwash
- a painkilling tablet, mouthwash, gel or spray
- corticosteroid lozenges
- a salt (saline) mouthwash
How to rinse with salt mouthwash
- Dissolve half a teaspoon of salt in a glass of warm water – warm water helps salt dissolve.
- Rinse your mouth with the solution, then spit it out – do not swallow it.
- Repeat as often as you like.
You can buy these without a prescription, but they may not always work.
A GP or dentist may prescribe stronger medicine to treat severe, recurrent or infected mouth ulcers.
You may have more than 1 ulcer at a time and they can change in size.
Mouth ulcers are not contagious and should not 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 can be a symptom of:
- hand, foot and mouth disease, which also causes a rash on the hands and feet
- oral lichen planus, which causes a white, lacy pattern inside the cheeks
- Crohn's and coelic disease (a condition that affects the digestive system)
- a weakened immune system from having a condition like HIV or lupus
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
Sometimes they're triggered by things you cannot always control, such as:
- 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
- medicines – including some NSAIDs, beta blockers or nicorandil
- stopping smoking – people may develop mouth ulcers when they first stop smoking