Warts are benign (not cancerous) skin growths that appear when a virus infects the top layer of the skin. Viruses that cause warts are called human papillomavirus (HPV). You are more likely to get one of these viruses if you cut or damage your skin somehow. Wart viruses are contagious. Warts can spread by contact with the wart or something that touched the wart. Warts are often skin-colored and feel rough, but they can be dark (brown or gray-black), flat, and smooth. Warts often go away without treatment. This is especially true when children get warts. In adults, warts may not disappear as easily or as quickly as in children. Although most warts are harmless, dermatologists do treat them. You should see a dermatologist if you cannot get rid of warts, warts hurt, or you have many warts. Dermatologists have many treatments for warts. The procedure used depends on the patient's age and health and the type of wart. Vascular lasers or ablative lasers are commonly used.