The leg manifests as a pit on one press, which is a manifestation of soft tissue edema, and most commonly, lower extremity venous thrombosis. There are the following contributing factors: First, patients with long bone fractures of the lower extremities undergo surgical internal fixation, and the venous blood flow in the lower extremities is slowed down when they are bedridden, which can easily lead to thrombosis. In the second case, injury to the endothelium of the lower extremity after trauma also creates an opportunity for platelet aggregation, which can easily lead to thrombosis. In the third case, hypercoagulable blood, especially in dehydrated patients or patients with advanced tumors, is also prone to thrombosis. In this case, the affected limb should be elevated to promote venous blood return, and active anticoagulation and microcirculation treatment should also be provided.