Not all HPV infections are symptomatic. 80% of people are infected with HPV, most people have a transient HPV infection that can be turned negative by their own immunity, only long-term persistent HPV infection for more than two years may lead to lesions. HPV6 and HPV11 infections can lead to condyloma acuminata, the incubation period of condyloma acuminata is about 3 months. HPV type 16, HPV type 18 and HPV type 33 are closely related to cervical cancer. Continuous infection for more than two years may lead to cervical lesions. About 60% of CIN1 will subside naturally, about 20% of CIN2 will develop into in situ cancer and 5% of CIN3 will develop into invasive cancer. At the beginning of cervical lesions, there may be no symptoms or only increased leucorrhea, but after the development of invasive cancer, there may be contact bleeding, bloody discharge or rice water-like discharge.