Warts are caused by HPV infection, and the main ways of transmission are sexual intercourse, mother-to-child transmission and so on. 1. Sexually transmitted: warts are almost always caused by sexual contact, because the HPV virus is present in semen and vaginal secretions. Transmission occurs during sex without the use of a condom, due to contact with HPV-infected skin and mucous membranes. It can also be transmitted anally through anal sex and orally through oral sex. 2. Mother-to-child transmission: for the invisible warts, there is also the probability of transmission, a few pregnant women in the process of normal delivery, due to the newborn from the vagina delivery, may also lead to warts transmission. 3. Indirect contact transmission: a few patients can be infected through non-sexual contact and the onset of disease. It is recommended to be clean, reduce high-risk sexual life, and if necessary, timely medical examination to confirm the diagnosis.