Lower extremity deep vein thrombosis is a clinical syndrome caused by various factors that lead to abnormal blood clotting and thrombosis in lower extremity veins, thus causing obstruction of lower extremity venous return flow. It often occurs in people with trauma, postoperative, long-term bed rest, pregnancy, postpartum, obesity, tumor patients, etc. Early thrombosis is easy to dislodge, which can cause pulmonary embolism and lead to sudden death. The following are some methods to prevent venous thromboembolism, which can help such patients. 1, early postoperative bed activity, or passive movement of the lower limbs. Patients who are postoperative or bedridden for a long time can perform foot massage or bending knee movement, foot dorsiflexion movement and get out of bed as early as possible. 2.Appropriate exercise to promote venous reflux. For those who travel long distances by airplane or car or boat, do three to five minutes of foot stretching every half hour. 3.Avoid sitting and standing for a long time Avoid sitting for a long time, you can lift the ankle, massage the calf, and carry out appropriate exercises for the legs. 4, drink more water to prevent blood stickiness. Drink 1 to 2 liters of water a day, equivalent to 10 to 15 glasses of ordinary glass. 5.Medical elastic stockings. Make a smooth difference of pressure between calf and thigh to promote venous blood return. 6.Air pressure pump. Help post-surgery, long-term bedridden patients and patients with mobility problems to massage the lower limbs, thus promoting venous return and preventing thrombosis. 7.Anticoagulant drugs For high-risk groups, anticoagulant drugs such as heparin, low-molecular heparin, warfarin, rivaroxaban, etc. can be used before or after surgery Note: If the lower limb pain or unilateral limb swelling occurs in high-risk groups, they should seek medical attention promptly and should not use measures such as massage, pushing, cupping, etc. to avoid serious consequences of thrombus dislodgement.