Cervical cancer screening is used to find abnormal changes in the cells of the cervix that could lead to cancer. Screening includes the Pap test and, for some women, testing for a virus called human papillomavirus (HPV).
The main cause of cervical cancer is infection with HPV. Cells that are infected with HPV appear different from normal cells under a microscope. Abnormal changes can be mild or they can be more serious. The more serious changes can lead to cancer if not treated.