Limb embolism has a rapid onset and the onset of the disease puts the limb and even the life at risk, so early diagnosis and proper treatment in a matter of seconds is essential. Lower extremity venous thrombosis is now a common disease that can occur at any age, but is more common in the elderly than in young people. People who stay in a certain position for a long time with little activity may be one of the factors of thrombosis. Therefore, it is advocated to do some work (classroom) exercises, walking, and limb exercises to increase blood circulation and prevent thrombosis, especially lower limb venous thrombosis. Limb embolism prevention should pay attention to the following points? 1, dietary factors: high-fat diet is an important factor in forming atherosclerosis and causing thrombosis, take measures such as quitting smoking and limiting saturated fatty acid intake. 2, smoking factors: some people concluded that 65% to 95% of thrombo-occlusive vasculitis patients 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 that of nonsmokers of the same age. 3, pregnancy and contraceptive pill factors: thrombosis is 6 times higher in the postpartum period than in the prepartum period, it is recommended to use tubal ligation or contraceptive tools to prevent pregnancy, which is especially important for women of childbearing age above middle age. 4, 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. 5.Physical 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 work for long hours, 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. 6, trauma and surgery factors: patients after serious trauma and major surgery are prone to thrombosis or thromboembolism. Therefore, patients after surgery should get up as early as possible, move early, drink more water, cough more sputum, do not curl up in bed all day, and assist patients to do lower limb extension and flexion exercise to improve blood circulation of feet, toes and limbs. For patients who cannot get out of bed for 24 hours after surgery, encourage deep breathing to promote blood reflux; assist patients to turn over and encourage limb movement in bed; for those who have difficulty moving, do up and down passive activities of the limbs or massage of the gastrocnemius muscle in order to improve blood flow to the lower limbs. Pay attention to changing the puncture site when infusing fluids. For example, patients after pelvic surgery should not use lower limb rehydration. 7. Disease factors: Common diseases such as chronic obstructive pulmonary disease, acute respiratory distress syndrome, bronchial asthma, hyperlipidemia, hypertension, unstable angina pectoris, myocardial infarction and so on. 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. 8.Wearing medical elastic stockings: elastic stockings can effectively prevent venous thrombosis in lower limbs and reduce the possibility of death from pulmonary embolism because they can significantly improve venous blood flow stagnation in lower limbs and promote venous blood return. It can also relieve or reduce the swelling of lower limbs caused by long distance travel.