Principle of medical compression stockings: Medical compression stockings are a product with the function of promoting venous blood flow back to the heart. The highest support pressure is established at the ankle and gradually decreases up the leg. In the gastrocnemius (calf belly) to 70%-90% of the maximum pressure value, in the thigh to 25%-45% of the maximum pressure value. This decreasing change in pressure can promote venous blood flow back to the lower extremities, effectively relieving or improving the pressure on the veins and venous valves of the lower extremities so that the clinical symptoms of venous insufficiency can be significantly improved, due to varicose veins and mild ankle swelling.