Swelling of the screw bone in the foot may be caused by several reasons: 1. It may be caused by an injury here. There are many types of injuries visible to this area. If there is a sprain or a direct violent blow, it may cause damage to the tendons, ligaments, bones and joints, which may lead to severe swelling in this area. In addition, old injuries in this area are often prone to long-term local swelling. 2. May be caused by edema-like lesions. Everything that can cause swelling in the lower extremities may manifest here as more pronounced swelling. Because this area is located in the lower part of the lower extremity, and the soft tissue coverage here is very thin, once the lower extremity is swollen, then it will be more obvious here. For example, this can occur if there is systemic heart or kidney insufficiency, hypothyroidism or malnutrition. 3. It may be caused by inflammation of the ankle joint. For example, if there is traumatic arthritis or osteoarthritis-like disease in the ankle joint, it can cause swelling here. Finally, this swelling may also be caused by the patient standing for long periods of time.