Anatomically speaking, lower extremity blood vessels include arteries and veins: 1. Lower extremity arteries: that is, the arteries from the common iliac artery to the toes, mainly supplying the blood supply to the skin, muscles, bones and other structures of the lower extremity; 2. Lower extremity veins: that is, the veins starting from the iliac vein to the toes, mainly accepting the blood from the skin, muscles and bones of the lower extremity back to the heart, including the deep veins, superficial veins and the traffic veins between the deep veins and superficial veins, with all the venous blood flowing back to the iliac veins and then to the inferior iliac veins and finally to the heart.