Canker sore is a painful disease of the mucous membrane of the mouth. Canker sore, also known as mouth sore among the people, is an oral ulcer that is seen in 20% of the population and causes pain, itching and burning.
How severe the canker sore pain is varies from person to person. Sometimes talking, eating or even swallowing causes pain.
If not treated timely and properly, canker sore tend to recur.