Warts are caused by the HPV, human papilloma virus. There are a hundred or so types of HPV and they do different things. Some types will cause common warts, some will cause genital warts and still other will make the person develop other kinds of warts. The virus spreads by contact. Common warts that tend to grow on the hands and fingers spread from skin to skin contact. These spread often through things like handshakes. Many of the other types are considered sexually transmitted diseases and spread from unprotected sex.

Warts spread easily and quickly. If you have a wart, be careful not to pick at it or touch it except to clean it or apply treatments. If you do contact it make sure you wash your hands carefully. Touching a wart and then touching another area of skin on your body or someone else