What are cold sores?

Cold sores are caused by a virus called Herpes Simplex, which comes in two varieties.

Herpes 1 , which occurs on the face; around and in the mouth, in the nose, around the eyes or most commonly on the lips.

Herpes 2 , which occurs on the genitals, on the penis, in and around the vagina, at the anus, on the buttocks and inner thighs.