Warts are contagious skin tumors (benign or noncancerous), "bumps," or "growths" that are caused by viruses.

Warts can occur singly or in clusters. Their appearance and size vary tremendously depending on where they erupt on the body and the degree of irritation or trauma they receive through daily wear of the skin. Warts usually disappear on their own, without any treatment, within several months. However, in some individuals, they may continue for years or reoccur at the same or different parts of the body.

Types: There are various types of warts. The most common wart is known as Verrucae vulgaris. It presents as a well-defined, rough-surfaced, roundish or irregular growth that is light gray, brown, grayish-black or yellow, and is usually firm to the touch. It most commonly appears on the knees, elbows, fingers, face, and scalp.

Periungual warts occur around the nail beds. Plantar warts occur on the sole of the foot, are very common, and often appear flattened due to the pressure of walking on them. When there are several plantar warts close together, they form a plague-like appearance called mosaic warts. Pedunculated warts are stalk-like and are common with age. They most commonly occur around the neck, chest, face, scalp, and armpits. Genital warts appear on or around the genitalia and are highly contagious.

Warts are caused by any of 35 viruses and are often a consequence of poor diet and nutrition, poor hygiene, and, in the cases of genital warts, unprotected sex. Warts also become more common as a consequence of aging with corresponding diminished immune function.

Caution: Some warts can turn into cancerous tumors. If they do not seem benign, consult with a physician immediately.