Have you ever wound up with an annoying little bump on your cheek or inside your lips after you accidentally bit inside your mouth? These obnoxious little sores are known as canker sores. 

Canker sores, also known as aphthous ulcers, are small, shallow lesions that develop on the soft tissues in your mouth or at the base of your gums and can make eating or talking uncomfortable. Unlike cold sores, canker sores don’t occur on the surface of your lips and they aren’t contagious. 

Types of Sores

There are several different types:


Canker sores can be painful and often make eating and talking uncomfortable. Although the exact cause of most canker sores is unknown, there are a number of things that may play a factor.

For minor sores, these include:

Canker sores as a whole are relatively common, with about 1 in 5 people getting them regularly. They are more common in women, perhaps due to differences in hormones, and can even run in families.

Are cold sores the same thing as canker sores?

No. Although these sores are often confused with each other, they are not the same. Cold sores, also called fever blisters or herpes simplex type 1, are groups of painful, fluid-filled blisters. Cold sores are caused by a virus and are extremely contagious. Canker sores are not caused by an infection and are not contagious. Also, cold sores typically appear outside the mouth — usually, under the nose, around the lips, or under the chin, while canker sores occur inside the mouth.

Conclusion and when to see a doctor

Although most canker sores are completely harmless, there are some situations when it would be good to visit your dentist or general practitioner to have them examined. If the sores are unusually large, they recur frequently, last for more than two weeks, extend to the lips, cause pain you can’t control with self-care measures, cause difficulty with eating or drinking, or you have a high fever alongside the canker sore, it’s necessary to have it checked by your doctor.