HPV stands for human papillomavirus. Flat warts grow because the skin is infected with HPV. HPV is a human papilloma virus, which can cause squamous epithelial hyperplasia of the skin and mucous membranes after infection. Clinical manifestations of common warts, flat warts, acromegaly and so on. Flat warts are prevalent in young people, lesions occur in the face, arms, back of the hand, etc., can last for many years, some patients can be improved by themselves, HPV virus can be divided into skin low-risk type, high-risk type; mucous membrane low-risk type, high-risk type. The HPV virus can be divided into low-risk and high-risk types; low-risk and high-risk types for mucous membranes. The actual warts can be left untreated, and some of them can go away on their own without leaving any traces, but if they continue to grow, it is advisable to go to the hospital to receive treatment. The treatment of flat warts can be done with topical retinol ointment as prescribed by the doctor, or with physical freezing and laser therapy, which has a good effect on the treatment.