A wart is a harmless skin growth caused by the virus called the human papillomavirus (HPV). There are more than 100 known types of 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. They are most common among children and young adults.