A wart is a skin growth caused by some types of the virus called the human papilloma virus (HPV). HPV infects the top layer of skin, usually entering the body in an area of broken skin. The virus causes the top layer of skin to grow rapidly, forming a wart. Most warts go away on their own within months or years. Warts can grow anywhere on the body, and there are different kinds. For example, common warts grow most often on the hands, but they can grow anywhere. Plantar warts grow on the soles of the feet.