Mouth ulcers

AGE Most common in adolescents and young adults	GENDER Slightly more common in females
LIFESTYLE Stress, illness, and poor general health are risk factors	GENETICS Sometimes run in families

Mouth ulcers are painful sores in the lining of the mouth, also called aphthous ulcers or canker sores.

Mouth ulcers are shallow, grey-white pits with a red border. They can cause pain, particularly when you are chewing spicy, hot, or acidic food. Mouth ulcers are extremely common and may occur singly or in clusters anywhere in the mouth. They may recur several times a year, but they usually disappear without treatment within 2 weeks.

The cause of mouth ulcers is not known, but the ulcers tend to occur in people who are run down or ill and before menstruation in women. Mouth ulcers are often stress-related. Injuries to the lining of the mouth caused by ill-fitting dentures, a roughened tooth, or careless tooth-brushing can also result in the development of mouth ulcers.

Occasionally, recurrent mouth ulcers are due to anaemia, a deficiency of either vitamin B12 or folic acid, or an intestinal disorder such as Crohn's disease or coeliac disease. In rare cases, they are due to the autoimmune disorder Behçet's syndrome.

Ulcers may also occur as a result of specific infections, such as herpes simplex infections. Rarely, an ulcer that enlarges slowly and does not heal may be mouth cancer.

Mouth ulcers usually heal without treatment. If you are prone to them, avoid possible irritants, such as spicy foods, and use a saltwater mouthwash. Over-the-counter treatments containing a corticosteroid to reduce inflammation or an anaesthetic are available in paste, lozenge, and gel form. The most suitable type depends on the site of the ulcer.

Consult a doctor or dentist about a mouth ulcer that does not heal within 3 weeks. He or she may carry out tests to look for an underlying cause.