Overview
Canker sores are painful white sores in the mouth. They usually begin with a tingling feeling, followed by a red spot or bump that turns white. Canker sores appear most often on the tongue, inside the cheeks, and inside the lips. They can be very painful and can make talking, eating, and drinking difficult.
A canker sore may form after an injury or stretching of tissues in the mouth, which can happen, for example, during a dental procedure or teeth cleaning. If you accidentally bite your tongue or the inside of your cheek, you may end up with a canker sore. Other possible causes are infection, certain foods, and stress. Canker sores are not contagious.
The pain from your canker sore should decrease in about a week, and it should heal in a few weeks. In most cases, a canker sore will go away by itself. Home treatment can ease pain and discomfort. If you have a large or deep canker sore that does not seem to be getting better after a few weeks, your doctor may prescribe medicine. Canker sores often come back again.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse advice line (811 in most provinces and territories) if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Where can you learn more?
Go to https://www.healthwise.net/patientEd
Enter D742 in the search box to learn more about "Canker Sores in Teens: Care Instructions".