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Canker Sores

Canker sores (aphthous stomatitis) are painful white ulcers in the mouth that appear most often on the tongue, inside the cheeks, and inside the lips. Unlike cold sores, canker sores are not contagious.

The cause of canker sores is not well-understood but may include injury or irritation inside the mouth, infection, and stress. Minor canker sores heal in 1 to 3 weeks.

Most people do not need to see a doctor for canker sores. The sores will get better on their own. To relieve pain, you might try over-the-counter medicine or change your diet to bland, soft foods.

ByHealthwise Staff
Primary Medical ReviewerKathleen Romito, MD - Family Medicine
Specialist Medical ReviewerArden Christen, DDS, MSD, MA, FACD - Dentistry
Last RevisedSeptember 14, 2012

WebMD Medical Reference from Healthwise

Last Updated: September 14, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.