What Causes Warts?

What causes warts? These miserable little lumps and bumps can show up on fingers, hands, toes and feet, among other places on the body-and in many cases, they appear seemingly without cause. Warts don't tend to be painful, but they can be very embarrassing. Are warts caused by touching toads, like the fairy tales claim or is there a different explanation for those bumps?

While toads may have glands that look like warts, the warts humans get are a viral issue. Warts are hard little patches of skin caused by HPV, or human papillomavirus. There are over 100 different types of HPV; the most common warts people encounter are types 1, 2 and 3:

• HPV Type 1 is the cause of the deep plantar warts on the soles of the feet and the palms of the hands.
• HPV Type 2 is associated with common warts, as well as some plantar warts, mosaic plantar warts and also filiform warts, which are the finger-shaped warts most commonly found on the face.
• HPV Type 3 is usually the cause of flat warts, also known as plane warts, which are also found on the face.

About 90 percent of genital warts are caused by HPV Types 6 and 11; approximately 70 percent of cervical cancers are caused by HPV Types 16 and 18. There is a vaccine for some types of HPV, including Types 6, 11, 16 and 18.

Because warts are caused by a virus, they can be very contagious. Warts can be spread by direct contact and also through using towels or other objects that have been touched by an infected person. Warts can be very stubborn and difficult to treat. Many people deal with recurrences and ongoing warts for months and sometimes they can continue to return for years.