Medically reviewed by Casey Gallagher, MD Many people experience acne on the face, including the lips. Certain foods and ...

Abscess If you notice a painful bump on the roof of your mouth, it could be an abscess—an infection that forms when bacteria ...

They can look similar on the surface, but their root causes (and treatments ... but never on the lips. A pimple is likely a raised red bump or whitehead, not a blister like a cold sore.