Dystrophic changes in the skin of the lower extremities are one of the symptoms of primary lower extremity deep vein valve closure insufficiency, which occurs mostly in workers who are permanently engaged in physical labor or standing, and has a higher incidence in farmers, hairdressers, athletes, surgeons, and other populations. The following tests can further understand superficial venous valve function, deep venous reflux of lower limbs and traffic venous valve function. 1, saphenous vein valve function test: patient lying down, lower limbs elevated, so that the veins empty, tie a tourniquet at the root of the thigh, compress the saphenous vein, then let the patient stand, release the tourniquet within 10 seconds, if there is a top-down venous refill, suggesting valve insufficiency. Applying the same principle, a tourniquet is applied to the popliteal fossa to test the function of the small saphenous valve. If the vein below the tourniquet is filled within 30 seconds before the tourniquet is released, it indicates that there is incomplete closure of the valves of the traffic veins. 2.Deep vein patency test: block the superficial thigh vein trunk with tourniquet, and watch the patient kick the leg or do downward stirring activity for more than 10 times. At this time, due to the contraction of calf muscle pump force the venous blood back to the deep vein, so that the varicose vein empties. If the superficial varicose vein is more obvious after the activity, and the strength is increased, and even there is swelling and pain, then it indicates that the deep vein is not open. 3.Traffic vein valve function test: the patient lies on his back, elevate the examined lower limb, and tie a tourniquet at the root of the thigh. Then wrap the first strong bandage from the toe up to the popliteal fossa, and then tie the second elastic bandage from the tourniquet down. If a varicose vein appears in the gap between the two bandages, it means that there is an incompetent traffic vein there. Other tests: ultrasound Doppler, volumetric tracing, lower extremity venous pressure measurement and venography. The nature of the lesion can be determined more accurately.