Genital warts, also known as venereal warts, or condylomata acuminata, are caused by the human papilloma virus (HPV). More than 100 types of HPV are known to exist. Low risk types (HPV 1, 2, and 3) cause warts on the hands, feet, and other parts of the body. Types (6 and 11) can cause warts on the genitals or anus (genital warts), and other types (HPV 16 and 18) can cause cancer of the cervix, external genitalia, and anus. The HPV types that cause genital warts only rarely cause cancer. Genital warts are usually sexually transmitted and all partners should be checked thoroughly. They can also be seen in infants who have been delivered vaginally to mothers with HPV in their genital tracts; therefore, alternate methods of delivery should be considered.
Only a small percentage of people infected with HPV will develop genital warts. Many people are "carriers" of HPV who may never develop warts, but may still be able to pass HPV to their sexual partners. The incubation period from contracting HPV until the development of warts may be several months although some people may not develop warts for years after contact with HPV. People who have lower immunity due to cancer, AIDS, organ transplantation, immune suppressive medications, or certain other medications are more susceptible.