Canker sore

Canker sore on the inside of the lip

A canker sore is a painful white ulcer in the mouth. They appear most often on the tongue, inside of the cheeks, and inside of the lips. Unlike cold sores, canker sores are not contagious. But in some people they keep coming back. Canker sores cause pain that may make it difficult to eat or drink.

Current as ofOctober 3, 2018

Author: Healthwise Staff
Kathleen Romito MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Adam Husney MD - Family Medicine
Arden Christen DDS, MSD, MA, FACD - Dentistry

Is it an emergency?

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If you are concerned about a possible poisoning or exposure to a toxic substance, call Poison Control now at 1-800-567-8911.

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