First, the causes of varicose veins in the lower extremities at present mainly include the theory of congenital poor structure of venous valve function and the theory of life environment pathogenesis. The main causative factors include: 1, family history: the prevalence of women with family history is significantly higher than those without family history; 2, long time standing work: the possibility of varicose veins in the lower extremities of people who work long time standing is 60% higher than those who do not stand for a long time; 3, tall and obese; 4, pregnancy: women who are pregnant due to the enlarged uterus compressing the iliac vessels and obstructing the blood return to the lower extremities is an important factor in the occurrence of varicose veins; 5, increased pressure, such as the prostate gland. varicose veins; 5, pressure increase, such as prostate hypertrophy, constipation, long-term chronic cough, etc.; 6, sitting work: the same as long-term standing workers, long-term sitting people are also prone to varicose veins, which is related to the bending of the lower limb veins when sitting does not facilitate reflux, coupled with no contraction of the calf muscle pump, blood stasis; Second, the diseases that may cause varicose veins in the lower limbs 1, the primary deep venous valve insufficiency; 2, deep vein thrombosis sequelae; 3, K-T syndrome: related to congenital malformation of veins; 4, iliac vein compression: anatomical factors and pelvic tumors and other factors; 5, inferior vena cava obstruction: Buga syndrome, mostly seen in young patients, with abdominal wall varicose veins.