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.

You cannot 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

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

How you can treat mouth ulcers yourself

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

A pharmacist can help with mouth ulcers

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