Human papillomaviruses can live on healthy skin without causing infection. However, when a human papillomavirus enters the body through small breaks in the skin, it can infect the skin cells beneath the surface, causing a wart to grow.

• A wart can take up to 9 months to grow before it becomes visible.¹
• Warts, particularly newer ones, are easily spread. They can spread to other parts of the body or to other people. You can reinfect yourself by touching the wart and then another part of your body. You can infect other people by sharing towels, razors, or other personal items.
• Common and flat warts can sometimes spread to the genitals and anus, especially in children.
• Plantar warts can be pushed beneath the skin's surface by pressure from standing and walking. A calluslike thickening of the skin slowly forms over most of the wart.
• Periungual warts can affect nail growth.
• It may be hard to get rid of warts after they develop. However, they generally go away on their own within months or years.²
• Just before warts disappear on their own, they may turn black.