Pulmonary embolism is a common clinical condition that can lead to acute chest pain. It is a disease syndrome caused by endogenous or exogenous emboli in the circulation blocking the pulmonary arteries. Pulmonary embolism is also a disease that requires careful clinical differentiation because of the intersection of the site of occurrence and disease factors with acute coronary syndrome. According to data from the United States, about 100,000 people die directly from pulmonary embolism each year in the United States, and about 100,000 deaths are complicated by pulmonary embolism. Pulmonary embolism is a common cause of death, and despite advances in diagnostic and treatment technology, it remains difficult to fully diagnose and effectively prevent this disease. Venous thrombosis is the most common pathological factor leading to pulmonary embolism, mostly seen in deep vein thrombosis of the lower extremities. The clinical presentation of pulmonary embolism is related to the size of the embolus and the degree of pulmonary vascular occlusion. Most patients are suspected of pulmonary embolism due to dyspnea, chest pain, aura syncope, syncope, and/or hemoptysis. Chest pain is a common symptom of pulmonary embolism, mostly due to pleural irritation caused by distal pulmonary embolism. Virchow suggests that there are several potential triggers for the development of venous thrombosis, including blood pooling, venous injury, and hypercoagulable blood. The following are the high-risk factors for pulmonary embolism: 1. Age factor: The age of pulmonary embolism is mostly between 50 and 65 years old, and the prevalence of children is about 3%. 90% of fatal PE occurs above the age of 50. The incidence of deep vein thrombosis is 10 times higher in women aged 20-39 than in men of the same age. 2.Decrease in activity: Long-term inappropriate bed rest due to lower limb fracture, paralysis, severe cardiopulmonary disease, surgery, etc., or healthy people usually have less limb activity, which reduces the driving force of venous blood flow and leads to blood stagnation and deep vein thrombosis. 3, varicose veins and thrombophlebitis: pulmonary arteriography and pulmonary perfusion scan show that 51% to 71% of people with lower extremity deep vein thrombosis may have combined pulmonary embolism. Pulmonary embolism occurs in patients with varicose veins and deep vein thrombophlebitis due to various reasons, once the intravenous pressure rises sharply or the venous blood flow increases suddenly, the embolus is dislodged and pulmonary embolism occurs. 4, cardiopulmonary disease: 25% to 50% of patients with pulmonary embolism have cardiopulmonary disease, especially patients with atrial fibrillation with heart failure are most likely to occur. 5, trauma: 15% of trauma patients have pulmonary embolism, among which tibial, pelvic and spinal fractures are often prone to pulmonary embolism; in addition, soft tissue injury and large burns can also be complicated by pulmonary embolism, which may be caused by the release of certain substances from injured tissues, damaging the endothelial cells of pulmonary blood vessels or causing hypercoagulation. 6, tumor: many tumors such as pancreatic cancer, lung cancer, colon cancer, gastric cancer, osteosarcoma, etc. can be combined with pulmonary embolism. 7, pregnancy and contraceptive pills: the incidence of venous thrombosis in women taking contraceptive pills is 4-7 times higher than in those not taking pills. It has been reported that intravenous infusion of estrogen can also induce pulmonary embolism. 8, other causes: obesity, certain blood diseases, diabetes, pulmonary cysticercosis, etc. The above are the risk factors of pulmonary embolism, but also include aspects that need attention in life. Objective factors such as age cannot be interfered with artificially, but such aspects as increasing activity, controlling blood sugar and weight can be done daily. In addition, regular annual checkups and lower extremity vascular ultrasound can be added for those who are at risk of hypercoagulation, and prompt medical attention should be sought when chest pain occurs.