Varicose veins include primary varicose veins and secondary varicose veins. Primary varicose veins involve only the saphenous veins and are most often seen in people who are constantly standing, physically active and sedentary. Secondary varicose veins are superficial varicose veins caused by deep venous lesions that increase deep venous pressure and destroy the valves in the connecting veins. The main reasons for the onset of the disease are: 1. Weakness of the vein wall and valve defects: the vein wall is relatively weak and can expand under the action of venous pressure, and the expansion at the valve sinus leads to the inability of the original venous valves to close tightly, resulting in relative valve insufficiency and backflow of blood. Valve dysplasia or absence, also can not play an effective role in preventing backflow, leading to the onset. 2.Long-lasting increase in intravenous pressure: venous blood itself, due to the role of gravity, produces a certain pressure on the valve, under normal circumstances will not cause damage to it, but when the pressure in the vein continues to rise, the valve will withstand excessive pressure, gradually relaxation, prolapse, so that the closure is incomplete. Most commonly seen in long-term standing work, heavy physical labor, pregnancy, chronic cough, long-term constipation, etc. 3.Age: With age, the vein wall and valves gradually lose their tension due to strain, and the valve closure becomes incomplete or the symptoms increase forcing the patient to seek medical attention. The causes of varicose veins are related to a variety of factors, and those that can be prevented need to be addressed.