1. Regional factors: The incidence of thrombosis is significantly higher in areas north of the Yellow River than in areas south of the Yangtze River. This may be related to temperature, diet, water quality and other factors. 2.Gender and age factors: There is no big difference between male and female. Thrombosis can occur in any age group, but after all, there are more elderly people than young people. Ethnicity and genetic factors: The level of coagulation factor VII in Far Easterners is much lower than that in Westerners of the same age, so the incidence of thrombosis is also lower than that in Westerners. There are 5% of thrombosis due to genetic defects, called hereditary thrombophilia, such as hereditary antithrombin deficiency, which occurs at the age of 10 to 25, and recurring, and can be inherited to offspring. In addition, after the same surgical procedure, patients with blood type A are prone to thrombosis, followed by type AB and B, and type O is less prone to thrombosis. 4, dietary factors: high-fat diet is an important factor in the formation of atherosclerosis and thrombosis, take measures to quit smoking and limit the intake of saturated fatty acids, can reduce the incidence of stroke by 57%, the mortality rate by 48.8%. 5, smoking factors: some people concluded that 65% to 95% of patients with thrombo-occlusive vasculitis have a history of smoking, smoking more than 20 cigarettes a day, for more than 20 years, the incidence of thrombosis is several times higher than non-smokers of the same age. 6, pregnancy and contraceptive pill factors: It is reported that the incidence of pulmonary embolism in pregnancy is 5 times higher than that of non-pregnant women, and the thrombosis in the post-partum period is 6 times higher than that in the pre-partum period. The blood coagulability of pregnant women increases during pregnancy, and the anti-blood coagulation effect is weakened. If combined with obesity, pre-eclampsia, obstructed labor, postpartum sepsis, etc., the thrombosis is further promoted. Therefore, pregnant women must undergo prenatal checkups. Women who take contraceptives containing estrogen and progestin for a long time have a higher incidence of thrombosis. According to foreign statistics, the risk of venous thrombosis is 7-10 times higher, the risk of myocardial infarction is 3-4 times higher, and the incidence of cerebral thrombosis is 9 times higher in those who take the pills than in those who do not. The risk of myocardial infarction is 28.5:2.7:1 for those who take medication for a long time (>5 years) compared to those who take medication for a short time (<2 years), and the ratio of myocardial infarction for those who take medication at an older age (>40 years), those who take medication at a younger age (<40 years) and those who do not take medication in the same age group is 4-11 times higher than that for those who do not take medication. However, there are 20 million women of childbearing age taking oral contraceptives in China, and no cases of thrombosis have been reported, which may be related to ethnicity, region, diet and other factors. It is recommended to use more tubal ligation or contraceptive tools for contraception, which is especially important for women of reproductive age above middle age. 7, obesity factors: appropriate to increase activity, control diet and reduce weight, reduce blood lipids, blood sugar, blood pressure and blood viscosity, is important for the prevention of thrombosis. 8, body position and activity factors: people who have been in a certain position for a long time with little activity may be one of the factors of thrombosis. For example, drivers, editors, clerks, typists, etc., as well as police officers, machine tool workers, teachers and bedridden patients who stand all day for a long time are prone to lower limb deep vein thrombosis due to slow blood flow and blood flow changes. Therefore, it is recommended to do some work (classroom) exercises, walking and limb exercises to increase blood circulation and prevent thrombosis, especially lower limb venous thrombosis. 9, trauma and surgery factors: serious trauma and patients after major surgery, prone to thrombosis or thromboembolism. It is reported that the incidence of deep vein thrombosis is 26% to 65% for large chest surgery, 5% to 42% for large abdominal surgery, 37% to 74% for hip surgery, 28% to 50% for prostate surgery, and 11% to 29% for major gynecological surgery. Therefore, after surgery, patients should get up as early as possible, early activity, drink more water, cough more sputum, do not curl up in bed all day. 10, disease factors: common diseases such as chronic obstructive pulmonary disease, acute respiratory distress syndrome, bronchial asthma, hyperlipidemia, hypertension, unstable angina, myocardial infarction, diabetes, infectious diseases, rheumatic diseases, systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, oral contraceptives, glomerulonephritis, nephrotic syndrome, late pregnancy, gestational hypertensive syndrome, atherosclerosis sclerosis, true erythrocytosis, venous thrombosis, pulmonary infarction, malignancy, surgical trauma, organ transplantation, idiopathic violent deafness, and hereditary thrombophilia. For the above diseases, the primary disease and thrombosis are causal, but thrombosis is a malignant factor contributing to the development of the primary disease, therefore, it is necessary to strengthen the examination of the pre-thrombotic state and give antithrombotic drugs for prevention and treatment as early as possible.