Definition of Canker sores:

A canker sore is a painful, open sore in the mouth, which is white or yellow and surrounded by a bright red area. A canker sore is benign (not cancer).

See also: Herpes

Causes, incidence, and risk factors:

Canker sores are a common form of mouth ulcer. They occur in women more often than men. They may occur at any age, but usually first appear between the ages of 10 and 40.

Canker sores usually appear on the inner surface of the cheeks and lips, tongue, soft palate, and the base of the gums.

Canker sores can run in families. They may also be linked to problems with the body's immune (defense) system. The sores may occur after a mouth injury due to dental work, aggressive tooth cleaning, or biting the tongue or cheek.

Canker sores can be triggered by emotional stress, dietary deficiencies (especially iron, folic acid, or Vitamin B-12), menstrual periods, hormonal changes, food allergies, and similar situations. They occur most commonly with viral infections. In some cases, the cause can not be identified.