www.sofootankle.com A wart on the bottom of the foot is a virus. They are commonly referred to as plantar warts because the bottom of the foot is referred to as the plantar surface of the foot. It’s a wart like you would get on the top of the hand or any other part of your body, but it’s on the bottom of the foot. It acts a little differently because the skin on the bottom of the foot is so thick. It’s like the wart has grown in, but it’s actually within that thick part of the skin. A wart is a virus that gets into the skin. It can get into the skin because of stepping on something. You could step on a toothpick at home, a needle, or something that can drive it in—even a rock. You can even get it at a local pool. That virus could be everywhere, and as your feet get wet and more porous, that virus can get into the skin and cause a wart to develop.