Genital herpes is a viral infection of the genitals. It is transmitted by sexual activity such as intercourse or oral sex and can affect both sexes (man and woman). Genital herpes is often associated with other sexually transmitted infections. It is an infection caused by the herpes simplex virus or HSV. There are two types of HSV and both can cause genital herpes. HSV type 1 most commonly infects the lips, causing sores, but it also can infect the genital area. HSV type 2 is the usual cause of genital herpes but can also infect the mouth during oral sex. The lesions can occur in and around the vaginal area, on the penis, around the anal opening, and on the buttocks or thighs. Occasionally, sores also appear on other parts of the body where the virus has entered through broken skin.