Warts are small, harmless growths that appear most frequently on the hands and feet. Sometimes they look flat and smooth, other times they have a dome-shaped or cauliflower-like appearance. Warts can be surrounded by skin that is either lighter or darker. Warts are caused by different forms of Human Papilloma Virus (HPV). They occur in people of all ages and can spread from person-to-person and from one part of the body to another. Warts are benign (noncancerous) and generally painless.