Canker sores are small sores that form in the mouth. They're usually white or yellow with a red border and can appear inside ...

Cold sores are painful blisters on the lips that can form unsightly crusts. They are very common and are caused by the herpes simplex virus. The medical name for facial cold sores is herpes labialis.

They can appear as round or oval sores with a white, yellow, or gray center and a red border. Common locations for mouth ulcers include the insides of the cheeks, lips, tongue, gums, or the roof ...