Pulmonary embolism mainly refers to the detachment of thrombi in the blood, leading to the obstruction of the main trunk of the pulmonary artery and its branches, causing a series of syndromes. Pulmonary embolism is an emergency in clinical practice. If the patient's circulation becomes unstable after the embolism, thrombolytic therapy should be considered. If the patient's respiratory circulation remains stable after the embolism, anticoagulation therapy can be considered. In clinical practice, pulmonary embolism is primarily diagnosed through pulmonary artery CTA examination to further clarify the diagnosis, and patients generally consult the respiratory medicine department.