The causes of cervical cancer are now clear; it is caused by an infection with the HPV virus. Generally, this virus needs to be carried for more than two to three years before it can infect and develop into cervical cancer. There is a process of carcinogenesis where normal epithelial tissue transforms into cervical intraepithelial neoplasia. If the HPV infection is not treated and continues, it could lead to cervical cancer. Thus, the development process is relatively long, typically requiring two to three years. It is recommended that sexually active women undergo cervical cancer screening to check for any pathological changes in the cervix, including HPV, TCT, and colposcopy examinations.