Symptoms of Canker Sores:

Canker sores begin as small reddish oval or round swellings, usually on the movable parts of the mouth such as the tongue and the inside linings of the lips and cheeks. These swellings usually rupture within a day, are covered by a thin white or yellow membrane, and become edged by a red halo.

The size of the sores varies from being an eighth of an inch wide in minor infections to an inch and a quarter wide in more severe cases. Fever is rare and rarely there is an association of canker sores with other diseases.

Usually a person will only experience a single or a few canker sores at a time. These sores generally heal within two weeks. Severe canker forms of the sore may leave scars. You should consult with your doctor if canker sores continues or worsens for more than two or three weeks.