Venous thrombosis has sequelae such as post-thrombotic syndrome and pulmonary embolism. 1. Post-thrombotic syndrome: When venous thrombosis is formed, with the gradual development of the disease, the venous blood flow will be hindered, and it will slowly develop into chronic venous insufficiency, which is also known as post-thrombotic syndrome, and it is mainly manifested as swelling of the lower limbs, hyperpigmentation, aggravation of varicose veins, and skin ulcers, and other symptoms. 2. Pulmonary embolism: If the venous thrombus dislodges and travels to the lungs, pulmonary embolism will be formed and affect the lung function. Most of the patients may suffer from dyspnea, chest pain, hemoptysis, fainting, restlessness, panic and other symptoms, and the serious situation can endanger the patient’s life. 3. Hypovolemic shock: After the occurrence of lower extremity venous thrombosis in a very few patients, occasionally the blood flow of lower extremity regurgitation decreases sharply, leading to the occurrence of hypovolemic shock. Therefore, if patients have venous thrombosis, they should go to the hospital in time, follow the doctor’s instructions to be treated, and regular review.