Herpes simplex type 1 or 2 viruses causes genital herpes, an infection of the skin and mucous membranes in the genital and surrounding areas. Herpes simplex virus usually spreads, when in contact with blisters. However, people with genital herpes can shed the virus from the genital area and infect others even without a blister being present. Cold sores on the mouth are a potential source of genital infection during mouth-to-genital contact. Medications can help decrease the severity of the herpes lesions and prevent recurrences, but they do not cure the infection.