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What is a Canker Sore?

A canker sore is a small blister located inside your mouth. These sores can occur anywhere inside your mouth - on the inside of your cheeks, the roof of your mouth, or on your tongue.

Sometimes before they appear, you can experience a burning or tingling in the spot where the canker sore is about to develop. Once they occur, they are an open sore that is white or grey coloured and sometimes they have a red border around the edge.

Most people have no idea what caused their canker sore, but if you put some thought into it, you can usually pinpoint a possible source.  Common causes include:

  • Damage to the lining of your mouth from a tooth, dentures, braces or even a hard toothbrush 
  • Eating extremely tart foods like lemons, oranges, pineapples or strawberries.
  • A weak immune system
  • Vitamin or mineral deficiencies
  • GI tract diseases like Crohn's or Celiac

The pain level can vary depending on the cause and severity of the canker sore.  If a sore is particularly painful, recurring or slow to heal, your doctor or dentist may recommend or prescribe medication to help it heal, reduce the pain or reduce the chances of recurrence. These can range from pain-reducing or antimicrobial oral solutions to steroid-containing ointments.

However, within a week or two, your canker sore should heal on its own without any treatment.