Canker sore: A small ulcer crater in the lining of the mouth that is often painful and very sensitive. Also known as an aphthous ulcer.
Canker sores are one of the most common problems that occur in the mouth. About 20% of the population (1 in 5 people) have canker sores at any given time. Canker sores typically last for 10-14 days and they heal without leaving a scar.
Picture of a canker soreThe word "canker" comes from the Latin "cancer" for crab. (In Latin "cancer" was once pronounced kanker from which came canker). Chronic ulcers might seem as hard as a crab shell.
For a full article, see Canker sores (Aphthous ulcers).
Canker sores appear in the mouth and can be fairly harmless but really painful. Learn more about them.
A canker sore is a painful, open sore in the mouth. Canker sores are white or yellow and surrounded by a bright red area. They are not cancerous.
Canker sore — Comprehensive overview covers causes, treatment and prevention of these painful mouth sores.
If you've ever had those open, shallow sores in your mouth, you know what a pain canker sores can be. So what can you do about them? Find out here.
Learn about canker sores (aphthous ulcer) causes, like allergies, immune disorders, vitamin and mineral deficiencies, smoking, stress, and female sex hormones.