There is no accurate figure for the chance of thrombosis after PICC placement, but there is a possibility of thrombosis after PICC placement. PICC is a foreign body, which can lead to thrombosis, and it is usually necessary to take active preventive measures after placement of the PICC. The full name of PICC is Peripheral Intravenous Centrifugal Catheterization. Since PICC is a foreign body, slow local blood flow, infection of the PICC tube and hypercoagulability of the blood are all triggers of thrombosis after the PICC is placed, preventive treatments are needed to deal with these risk factors. First of all, it is necessary to take active care of the patient after PICC tube placement, avoid infection symptoms, seal the tube regularly, and actively carry out anticoagulation, which can effectively reduce the incidence of thrombosis by adding heparin and so on in the sealing liquid under the guidance of the doctor. If there is swelling and numbness in the limbs after PICC tube placement, it is necessary to consult a doctor in time for examination to avoid thrombosis, and after the diagnosis is clear, it is necessary to cooperate with the doctor for treatment to avoid deterioration of the situation.