Foot long a lump and not accompanied by pain, common causes are callus, fracture deformity healing, chondroma and so on. 1. callus: also known as callus, due to long-distance running, mountaineering, standing for a long time to work, resulting in repeated friction of the plantar skin, keratin layer hyperplasia caused by the general can be no pain. 2. Fracture deformity healing: if the foot has been injured, resulting in metatarsophalangeal joint fracture, no reset treatment or displacement of the fracture end after reset, the fracture deformity healing, protruding to the sole of the foot, there may be a lump-like swelling, may not be accompanied by pain. 3. Chondroma: chondroma can appear in the metatarsophalangeal joints of the foot, it is a kind of benign bone tumor, after the abnormal proliferation of cartilage tissues, the metatarsophalangeal joints gradually swollen, and finally protruded in the subcutaneous, forming a lump, there may be no obvious pain in the early stage, and pain can appear after gradual development. The cause of the pimple and not accompanied by pain in the heart of the foot is more reasons, but also with corns, eczema, plantar warts and other diseases, it is recommended to consult a timely, clear cause, and then targeted treatment.