Warts are small, usually painless growths on the skin caused by a virus. They are generally harmless. However, warts can be disfiguring and embarrassing, and occasionally they itch or hurt (particularly on the feet).

The different types of warts include:

• Common warts usually appear on the hands, but can appear anywhere.
• Flat warts are generally found on the face and forehead. They are common in children, less so in teens, and rare in adults.
• Genital warts are usually found on the genitals, in the pubic area, and the area between the thighs, but can appear inside the vagina and anal canal.
• Plantar wartsare found on the soles of the feet.
• Subungual and periungual warts appear under and around the fingernails or toenails

The typical wart is a raised round or oval growth on the skin with a rough surface. Compared with the surrounding normal skin, warts may appear light, dark, or black (rare). Most adults are familiar with the look of a typical wart and have little trouble recognizing them. Unusual warts with smooth surfaces or flat warts in children may be more difficult for parents to recognize.

Common warts tend to cause no discomfort unless they are in areas of repeated friction or pressure. Plantar warts, for example, can become extremely painful. Large numbers of plantar warts on the foot may cause difficulty running and even walking.

Warts around and under your nails are much more difficult to cure than warts elsewhere.

Some warts will disappear without treatment, although it can sometimes take a couple years. Treated or not, warts that go away often reappear. Genital warts are quite contagious, while common, flat, and plantar warts are much less likely to spread from person to person. All warts can spread from one part of your own body to another.

Because people generally consider warts unsightly and there is often a social stigma, treatment is often sought.

• Small, hard, flat or raised skin lesion or lump
• Abnormally dark or light skin surrounding the lesion
• Numerous small, smooth, flat (pinhead sized) lesions on forehead, cheeks, arms, or legs
• Rough, round, or oval lesions on soles of feet -- flat to slightly raised -- painful to pressure
• Rough growths around or under fingernails or toenails

Warts can generally be diagnosed simply by their location and appearance. Your doctor may want to cut into a wart (called a biopsy) to confirm that it is not a corn, callus, or other similar-appearing growth.