Warts are benign growths caused by human papilloma virus infection of the skin and mucous membranes, and can be spread by direct or indirect contact between patients and healthy carriers of the virus. The cause of common warts is the infection of human papilloma virus, which enters the epithelial cells from the breaks in the skin and mucous membranes and replicates, proliferates, and causes the epithelial cells to have abnormal differentiation and hyperplasia, leading to the formation of skin warts. The warts are contagious to both patients and healthy carriers, and can be transmitted through direct or indirect contact, and immunocompromised and traumatized people are more susceptible to the disease. Warts are often found on the hands, and trauma to the hands and immersion in water are common triggers. The actual dermatology department of the hospital is recommended to treat the warts with topical medication such as retinoic acid ointment, imiquimod ointment, or physical therapy such as liquid nitrogen freezing and laser.