Warts are an infectious disease of low infectivity caused by a virus.
Warts may be named by their location and appearance. On the soles of the feet they are called planter warts. Around and under the fingernails or toenails they are periungual or subungual warts, respectively. Common warts on the hands, arms, legs, and elsewhere are verrucae vulgaris but often just called common warts. These are seen less often in adolescents and seldom in adults.