Mouth ulcers are common and should clear up on their own within a week or 2. But see a GP or dentist if you have a mouth ulcer that lasts longer than 3 weeks.

Mouth ulcers are rarely a sign of anything serious, but may be uncomfortable to live with.

They 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 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

You can buy these without a prescription.

Find a pharmacy

See a dentist or GP if your mouth ulcer:

A GP or dentist may prescribe stronger medicine to treat severe, persistent or infected mouth ulcers.

Possible treatments include:

• steroids given as either a mouth spray, tablets that dissolve in your mouth or tablets that can be dissolved in water
• painkilling gels, ointments, sprays or tablets
• mouthwashes to kill or remove any germs in your mouth

You may have more than 1 ulcer at a time.

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. They can also appear as a small group of pinhead-sized ulcers inside the mouth.

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 vitamin deficiency, such as iron, zinc, folic acid, vitamin B or vitamin D
• medicines – including some NSAIDs, beta blockers or nicorandil
• stopping smoking – people may develop mouth ulcers when they first stop smoking

If you have several mouth ulcers, it 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 disease and coeliac disease (conditions that affect the digestive system)
• a weakened immune system from having a condition like HIV or lupus