I have a bump on the inside of my lower lip. it has a head like a pimple but it looks clear like a blister. it hurts and came from nowhere. what is it?

Herpes Simplex 1: If it is painful, as in stinging, this is likely HSV-1 or herpes type type one. These are often called cold sores and the most common mode of contraction is kissing. They are harmless, but painful and can be associated with acute stress (physical or mental) such as getting the common cold, flu, test taking time, menstruation, pregnancy, etc. If they do not resolve or become more painful discuss