How did sole grow a hard knot to resemble cocoon to do

The sole has a hard knot like a cocoon, if accompanied by tenderness, a single occurrence or a small number, to consider corns. Corns it is due to long-term friction or pressure, resulting in local skin keratinization caused by frequent standing or walking people are prone to corns, can be external corns cream, the effect is not good can consider surgical excision. If the pain is not obvious, generally no pain or slight pain when walking, consider plantar warts, single or multiple occurrence, it is common warts occurring in the soles of the feet, is a viral skin disease, can do laser, freezing and other physical therapy.