A WART is an intraepidermal skin tumor caused by various viruses. The many varieties of warts that exist are named by the way
they appear or where they are located. A wart is a small, circumscribed
tumor of the outer or horny layer of the skin. There are flat and smooth
warts as well as elevated warts, warts that are firm and rise from the
surrounding skin.
Mainly caused by the Human Papillomavirus (HPV), warts vary in size and may be painful, especially when located on the feet (plantar warts). The Human Papillomavirus belongs to a family of viruses that cause warts and has been implicated as a possible cause of genital cancers and, more recently, cancers and other abnormal growths of the eye.