Canker sores, medically referred to as aphthous ulcers, can be a painful nuisance. These small, shallow ulcers appear in the ...

Canker sores are small sores that happen inside the cheeks and lips, at the base of the gums, and on or under the tongue. They can make it painful to eat, drink, or even brush teeth. Canker sores are ...

If you've ever had a canker (say: KAN-kur) sore, you know that these small mouth sores can cause major pain. A canker sore can show up on the inside of your lip or cheek, under your tongue or at the ...