The causes of vascular bending are divided into arteries and veins. Arteries bend mainly due to decreased elasticity of the blood vessels, high blood pressure or other factors, resulting in excessive pressure on the blood vessels, which can lead to tortuosity and dilatation. Vein bending is mainly due to venous pressure in the veins, after a longer period of time will cause venous wall thinning, tortuous and dilated, both because of the role of the mechanism is different, so the appearance of the site is also different. Arterial vascular buckling usually occurs in locations where arterial pressure is higher, such as closer to the aorta, while venous vascular pressure is highest in the lowermost part of the body, and is therefore often found in the lower legs and feet.