The symptoms of swelling and bulging on the back of the foot are commonly caused by the following: a. Acute injury, due to injury during sports or walking, local congestion, bleeding, edema, inflammatory reaction, swelling and bulging symptoms. In severe cases, it will lead to fracture, fracture after displacement will also lead to local deformity bulge. Second, it is seen in chronic strain injury, prolonged standing, walking or cumulative injury, resulting in bone degeneration, osteophytes, and tendon sheath cysts, which can lead to local pressure swelling and bulging symptoms. Third, see other systemic diseases, such as diabetes, gout, can be due to poor local blood circulation, or uric acid crystals deposited around the joint, resulting in swelling, bulging and pain symptoms.