Mouth Ulcers

Painful sores in the lining of the mouth, also called aphthous ulcers or canker sores

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

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 toothbrushing 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 an antiseptic or pain-relieving mouthwash. Over-the-counter treatments containing a corticosteroid to reduce inflammation or an anaesthetic are also available.

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.

Mouth ulcer

The typical grey-white pit of a mouth ulcer has developed inside the lower lip of the mouth shown above.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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