There are two types of herpes simplex virus: type 1 (HSV-1 or oral herpes) and type 2 (HSV-2 or genital herpes). Most commonly, HSV-1 causes fever blisters or cold sores around the mouth and lips. HSV-1 can cause genital herpes, but most cases of genital herpes are caused by HSV-2. In HSV-2, the infected person may have sores around the genitals or rectum. Although HSV-2 sores may occur in other places, these sores usually are found below the waist.