Plantar warts almost always appear on the bottom (sole) or side of the foot — especially on areas that bear pressure, like the heel or ball of the foot. They are caused by the human papillomavirus (HPV), which enters through tiny cuts or weak spots in the skin.
Why they form on the foot:
- HPV thrives in warm, moist environments, like locker rooms, public showers, and pool decks.
- The pressure from walking or standing forces the wart inward, often making it feel like a painful stone in your shoe.
- They can also appear in clusters (called mosaic warts).
Common symptoms of plantar warts:
- A small, rough, grainy bump on the sole of the foot
- A thickened area of skin (often mistaken for a callus)
- Tiny black dots (clotted blood vessels, often called “wart seeds”)
- Pain when walking or standing