There may be several reasons for the swelling of the left foot screw bone: 1, trauma, if the external impact may be, resulting in the left foot screw bone swelling, pain, need to immediately consult the orthopedic emergency room, take an X-ray, to see whether the fracture. If there is a fracture, according to the location and degree of fracture, and then develop a specific treatment plan, if there is no fracture, may be due to trauma, resulting in the left foot screw bone stasis blood accumulation, thus swelling, pain, with a slight limitation of activities, treatment can be given to the Sivipu analgesic, pulse blood Kang blood circulation, physical therapy to ease the pain. 2, tenosynovitis, if the left foot is a long-term exposure to cold or fatigue, which may result in the screw bone, there is sterile inflammation, resulting in local pain, swelling, and pain, and then the left foot will be affected. If the left foot is exposed to cold or exertion for a long time, it may lead to aseptic inflammation at the screw bone, which may cause local pain and swelling. 3, rheumatic diseases, if there are rheumatic diseases, such as gout or rheumatoid arthritis, etc., the attack may also lead to swelling and pain at the screw bone of the left foot.