Warts are small, self-limited tumors caused by one of over 100 types of human papilloma viruses . Warts are raised bumps on your skin. Warts are usually painless.
But a wart that grows in a spot where you put pressure, such as on a finger or on the bottom of the foot, can be painful. A wart is a skin growth. Tiny blood vessels grow into the core of the wart to supply it with blood.