Genital herpes is a sexually transmitted viral infection affecting the skin or mucous membranes of the genitals.

Genital herpes is caused by two viruses:

• Herpes simplex virus type 2 (HSV-2)
• Herpes simplex virus type 1 (HSV-1)

Herpes simplex virus type 2 (HSV-2) causes most cases of genital herpes. HSV-2 can be spread through secretions from the mouth or genitals.

Herpes simplex virus type 1 (HSV-1) most often causes herpes infections of the mouth and lips (commonly called cold sores or fever blisters). HSV-1 can spread from the mouth to the genitals during oral sex.

Herpes simplex virus (HSV) is spread from one person to another during sexual contact. You may be infected with herpes when your skin, vagina, penis, or mouth comes into contact with someone who already has herpes.

Herpes is most likely to be transmitted by contact with the skin of an infected person who has visible sores, blisters, or a rash (an active outbreak), but you can also catch herpes from an infected person's skin when they have NO visible sores present (and the person may not even know that he or she is infected), or from an infected persons mouth (saliva) or vaginal fluids.

Because the virus can be spread even when there are no symptoms or sores present, a sexual partner who has been infected with herpes in the past but has no active herpes sores can still pass the infection on to others.

Genital HSV-2 infections is more common in women (approximately 1 of every 4 women is infected) than it is in men (nearly 1 of every 8 men is infected).