Canker sores are painful sores that usually appear inside your mouth, at the base of your gums. While these are not ...

Unlike cold sores, they are not contagious. The exact cause of canker sores is unknown, but they may be triggered by factors like stress, minor injuries (e.g., biting your cheek), acidic or spicy ...

What are canker sores? If you’ve ever had one, you probably remember exactly how it feels. These sores are small, painful ulcers that can develop in your mouth for a variety of reasons.