Most women will be infected by HPV (human papillomavirus, a virus which causes almost all cases of cervical cancer) during their lifetime--making cervical cancer screening one of the most important preventive services for women. HPV is a common sexually transmitted virus that most infected people never realize they have.

In addition to cervical cancer, HPV can lead to a variety of other health problems and cancers such as common warts, genital warts, and cancer involving the vulva, vagina, anus, and head and neck. HPV infections rarely result in cervical cancer as, in most women, the immune system will eliminate the infection and allow cervix cells to return to normal. However, some HPV infections may persist in the cervix for years and these chronic infections may lead to cellular changes that can progress to cancer.