Patients taking warfarin are advised that prothrombin time is best controlled between 2-3, which is relatively safe and can also play a role in preventing thrombosis. It is recommended that while taking warfarin, attention must be paid to regular monitoring of the international normalized ratio, which helps to find out early whether the patient is currently taking the medication qualified to meet the standard, and if not, to gradually increase the dose of the drug in small doses. If it exceeds 3, the dose should be reduced in small doses. Because if you just eat warfarin, but did not achieve the efficacy between 2-3, about the same as not eating this drug, so at present in the clinic, for non-valvular disease, generally oral new anticoagulants are relatively easy to consume, the representative drugs are dabigatran, rivaroxaban and so on.