Herpes usually causes painful blisters that break open and form sores.
The most common sites of outbreaks are the genitals, mouth and rectal area. Both types of virus are transmitted by direct contact with infected skin or mucous membranes. A person can become infected with the virus by contact with infected skin on the genitals, mouth, rectal area, or buttocks. The infection is often passed from person to person during sexual intercourse. During oral sex, genital herpes can pass to the lips and mouth and, conversely, oral herpes on the lips can pass to the genitals.