Pulmonary embolism is a general term for a group of clinical syndromes that includes pulmonary thromboembolism, fat embolism syndrome, amniotic fluid embolism, and air embolism. The type of anticoagulation required is pulmonary thromboembolism, and the duration of anticoagulation varies from person to person, and the course of therapy needs to be determined by the patient’s risk factors. The usual course of oral anticoagulants is at least 3 months. If the patient’s risk factors can be eliminated in a short period of time, estrogen has been applied or temporary braking is sufficient for 3 months of anticoagulation; if the cause of the embolism is unknown, anticoagulation needs to be continued for at least 6 months. For patients with recurrent pulmonary thromboembolism or long-term risk factors, the duration of anticoagulation therapy should be extended to 12 months or more, or even lifelong anticoagulation. It is important to note that risk factors are hereditary and acquired, and need to be diagnosed by a physician. Anticoagulation therapy may be associated with bleeding complications, which require regular monitoring of relevant test results and anticoagulation therapy under the guidance of a physician.