Leg vein thrombosis may be dissolved in 12-24 hours, or it may take about 5 months to dissolve, depending on the time of thrombus formation, whether it is in the acute stage or not, the dissolution time is different, analyzed as follows. 1.12-24 hours: when the formation time of leg vein thrombosis is short and in the acute stage, interventional surgery can be used to dissolve the thrombus, generally 12-24 hours the thrombus can be dissolved, oral anticoagulant medication after the operation, review of ultrasound of both lower limbs and other tests did not find thrombus, clinical swelling, pain and other symptoms improve to reach the standard of cure. 2.5 months or so: patients with thrombosis for a long time, chronic thrombosis generally oral anticoagulant drugs, hospital injection of low molecular heparin for anticoagulation, while the treatment period to elevate the lower limbs or supplemented with compression stockings, generally about 5 months thrombus can be dissolved, but the thrombus may be along the blood circulation into the lungs caused by pulmonary embolism, so the emergence of chest pain, hemoptysis, difficulty in breathing when the timely consultation. Thrombus dissolution should be based on the etiology and cause of formation, choose different treatment, it is recommended that patients go to regular hospitals to do a systematic examination, according to the doctor’s recommendations for treatment, do not blindly self-governance, so as not to delay or aggravate the condition.