Plantar warts with black roots inside are usually bleeding spots, which are formed when capillaries rupture and bleed. Plantar warts are mainly caused by human papillomavirus infection, the foot is subjected to long-term friction, low immunity and other reasons may also trigger the disease. Patients mainly present with rough plaques that are yellowish or tawny in color, surrounded by a thickened keratin ring. After removing the keratin layer, it will be found that the center of the lesion will appear line or dot-like out of the point, usually formed after the capillary rupture, is a normal condition, usually do not need special treatment, but with the aggravation of the disease, may be painful when walking or standing. If you find black roots inside the plantar warts, you can go to the hospital and consult the doctor to clarify the relevant matters.