The Causes of Canker Sores

Pursuing the Perfect Smile

The Causes of Canker Sores

Canker sores are small sores that form inside of the cheeks or lips and on the gums. They start out as a slight red bump that produces a burning or tingling sensation. When they fully form, they are white or yellow and may be surrounded by a small red border. Canker sores are not to be confused with cold sores. Cold sores form on the outside of the mouth and are caused by the herpes simplex virus, while canker sores always appear inside the mouth. Unlike cold sores, canker sores aren’t contagious.


While canker sores seem to appear for no apparent reason, they are often caused by irritation or trauma to the inside of the mouth. For example, you might develop a canker sore after biting your lip or the inside of your cheek. You might also develop one if you brush your teeth hard enough to irritate your gums or if a dental appliance rubs against the inside of your cheek. Stress, a weakened immune system, and eating spicy or acidic foods such as citrus fruit can also contribute to the formation of a canker sore.


There is no cure for canker sores, but the pain they cause can be managed through a treatment course. Most canker sores go away in 7-10 days, but if you have a canker sore that won’t go away or you’re experiencing cold sores, contact Dr. Petinge. Our Petinge Dental team considers the holistic health of all of our patients to be our number one priority, and we are more than happy to answer any questions you may have about your own dental health.