Herpes on your lip! You can do this to prevent such a nasty cold sore
It starts with a tingling in your lip and then: a small, painful, round blister. Many people will recognize the feeling of a cold sore. The culprit, the herpes simplex virus, is one of the most common viral infections in humans. The sun fuels the virus. Seven facts and myths about the cold sore. Plus eight tips to prevent it.