Canker

Canker is when you get a little boo-boo inside your mouth. It's like a little sore or bump that can be painful and make it hard to eat or talk sometimes. Cankers can be caused by things like biting your cheek or lip, or by eating something that's too hot or spicy. They usually go away on their own in a few days or a week, but you can help them feel better by putting some special medicine on them or avoiding things that might make them worse, like eating really crunchy or rough foods.