A wart is generally a small, rough tumor, typically on hands and feet, that can resemble a cauliflower or a solid blister. Warts are common, and are caused by a viral infection, specifically by the human papillomavirus (HPV) and are contagious when in contact with the skin of another. It is also possible to get warts from using towels or other objects. They typically disappear after a few months but can last for years and can reoccur. A few papilloma viruses are known to cause cervical cancer.

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 it. Unusual warts with smooth surfaces or flat warts in children may be more difficult for parents to recognize.

Some warts will disappear without treatment, although it can sometimes take a couple of years. Treated or not, warts that go away often reappear. All warts can spread from one part of the body to another. Unsightly or painful warts can be treated. Warts around and under the nails are much more difficult to cure than warts in other places.

Avoiding direct skin contact with a wart on someone can contribute to preventing the infection.