A mouth ulcer or canker sore is a painful open sore inside the mouth caused by a break in the mucous membrane. The condition is also called aphthous stomatitis.

Table of contents
1 Symptoms
2 Causes
3 Treatment

Symptoms

A mouth ulcer appears as a yellow or grey oval, on average about 3 mm across, with an inflamed red border. The ulcer may be accompanied by a painful swelling of the lymph glands below the jaw, which can be mistaken for toothache.

Causes

The immediate cause of mouth ulcers is unknown, but factors that appear to provoke them include
stress and illness, damage from rough teeth, and deficiencies in vitamin B12 and folic acid.

Other disorders can cause mouth ulcers, including oral thrush, oral cancer, leukoplakia, gingivostomatitis, oral lichen planus and herpes simplex. The treatment depends on the cause.

Treatment

Mouth ulcers normally heal without treatment within seven to ten days. The symptoms can be alleviated by medicines such as mouthwashes, pastilles and pain-relieving gels, which are available in drugstores. Treatments based on antibiotics and steroids are reserved for severe cases, and should be used only under medical supervision. Good oral hygiene and avoidance of spicy foods can help to reduce the pain. The miracle cures that are advertised should be viewed with scepticism.