Description of the disease:Started to appear left leg soreness and pain in the left lower abdomen near the groin, need to be assisted to walk, the next day the left leg swelling and hardening and can not walk, the left leg more obvious tingling sensation. After examination, he was diagnosed with left lower extremity deep vein thrombosis. After more than 20 days of treatment, ultrasound review concluded that the left lower side of the common iliac, external iliac, common femoral, superficial femoral, N, posterior tibial vein lumen can be seen in the low-moderate echogenic thrombus filling, the periphery can be seen in the strip of blood flow signals (superficial femoral vein is not detected in the exact blood flow signals). The cause of thrombosis has not yet been identified, and I would like to ask if there is a need to continue to look for the cause. 2. My doctor said that I can be discharged from the hospital tomorrow, but my left ankle and the surface of the foot are still swollen, and there is a tingling sensation on my left ankle after walking for more than 10 minutes, is it a sequela of the tethered blood? Can it be relieved? There are some DVTs for which no cause can be found. These are collectively called idiopathic DVTs, which actually means that people have not yet discovered the mystery, not that there is really no cause. There are some known factors: trauma, surgery, radiotherapy, prolonged bed rest, estrogenic contraceptives, tumor hypercoagulability, hypercoagulability due to autoimmune diseases and damage to the venous endothelium, congenital defects in anticoagulant mechanisms, and so on (and there should be many more) that can lead to the formation of DVT. The treatment of DVT is mainly anticoagulant therapy, which aims at: preventing further progression of the thrombus and assisting the body’s fibrinolytic system to gradually dissolve the thrombus. The warfarin you are taking is the most classic anticoagulant available. In addition to anticoagulation, interventional thrombolysis is also one of the main treatment means, but the effect is unstable, especially for patients who have already passed the acute stage, the effect is especially poor, and the cost-effectiveness ratio is low. Then, there is compression stocking therapy, which helps to relieve symptoms and slows down the time to onset of DVT sequelae. Both treatments, taking anticoagulants and wearing compression stockings, are very basic, but important. It must be adhered to. As for the improvement of symptoms, this can not be rushed, once the deep vein thrombosis is formed, it is a chronic disease, we need to have persistent perseverance and patience, so that the habit will become natural, and the symptoms will gradually improve.