It is important to understand that there is a wide variation in obtaining a satisfactory dose of warfarin. There is a risk of bleeding due to overdose or changes in the condition of the original disease due to underdose. Patients are advised to keep in mind the following: 1. After discharge from the hospital, take the oral dose of warfarin once a day according to the oral dose at the time of discharge, and patients are not allowed to change the dose of medication. 2. Check blood coagulation once a week, and send the results to WeChat after taking photos. Strictly follow the reply medical advice. 3.If subcutaneous bruising, gum bleeding, black stool and hematuria occur, stop the medication in time and come to the hospital for consultation.