A hard lump on the heel may be caused by corns, tendon sheath cysts, bone spurs, common warts and other diseases, the patient should consult a doctor in a timely manner to clarify the cause of the disease and then carry out the appropriate treatment. 1. corns: a hard lump on the heel may be caused by corns, which is caused by long-term friction and extrusion of the skin of the foot, and there will be pain, can be used locally salicylic acid, urea treatment, and if necessary, surgical treatment. 2. Tendon sheath cysts: a hard lump on the heel may also be caused by tendon sheath cysts, which have a smooth surface and may cause numbness when pressing on the nerves, and can be removed through surgery. 3. Bone spurs: a hard lump on the heel may also be caused by bone spurs, some patients may have joint pain, impaired mobility, the patient should pay attention to appropriate exercise, the pain is serious can be surgically removed. 4. common warts: a hard lump on the heel may also be common warts, which can be treated with laser or freezing. There may be other reasons for a hard lump on the heel, so you need to actively consult the doctor to clarify the cause of the disease and then carry out targeted treatment, the above drugs and operations should be carried out under the guidance of the doctor.