F2 and thrombophilia: Virchow’s triad of hypercoagulability, venous stasis, and endothelial injury represents common risk factors, which can be categorized into genetic factors—including thrombophilia (factor V Leiden mutation, prothrombin gene mutation, protein C deficiency, protein S deficiency, and hyperhomocysteinemia)—and acquired factors, such as prolonged immobilization, malignancy, recent orthopedic surgery, indwelling venous catheters, obesity, pregnancy, smoking, and the use of oral contraceptives.