One is to review regularly, and the other is not to stop the medication on your own in the middle of the day. Warfarin is an antagonist of vitamin K, which is a substance that stops bleeding. Warfarin acts as an anticoagulant by depleting the vitamin K in the body. When you take warfarin orally, you must prolong the prothrombin time (PT) in your body to a certain level in order for the anticoagulant effect to be effective and the treatment to be effective. This is now usually expressed using the International Normalized Ratio (INR). In general, the INR should be extended to 2.0-3.0. If the INR value does not reach 2.0, it cannot play an effective anticoagulant role, and when the INR value exceeds 3.0, the anticoagulant effect is not only no longer enhanced, but the risk of bleeding increases, which is the side effect of this drug warfarin. Many patients who do not monitor INR cause gastrointestinal hemorrhage, subcutaneous bruising throughout the body resulting in “blood lessons” causing emergencies should be very careful, so be sure to regularly review INR levels during oral warfarin to allow the drug to achieve the best anticoagulant effect. Please obtain the results of the blood tests and inform your doctor in a timely manner to determine if you need to adjust the dosage of warfarin and the time of the next review. It is common for some patients to stop taking warfarin after some conditions, which is unacceptable and sometimes even dangerous. A foreign study showed that the risk of recurrence of pulmonary embolism increased exponentially in patients who were treated with regular anticoagulation therapy, but not in those who were treated with regular anticoagulation therapy. For those patients who are irregularly discontinued and have to undergo anticoagulation again, they cannot simply take oral anticoagulants again on their own, but need to be treated with heparin or low-molecular heparin first, followed by oral warfarin, as in the case of initial anticoagulation. This is dictated by the characteristics of the action of a drug like warfarin. Otherwise the complex interaction of the drug with the coagulation mechanisms in the body can form a clot again. This will not only increase the burden on the treatment, but also cause another blow to the organism.