A general plasma D-dimer quantification of less than 200 μg/L is normal and is a major factor in the determination of the fibrinolytic system. Once elevated, it is of some significance in the diagnosis and treatment of fibrinolytic system disorders and plays an important role in the diagnosis and treatment of deep vein thrombosis, pulmonary embolism, and diffuse intravascular coagulation. Monitoring during pregnancy is also of some significance, as once this value is elevated, it may increase the risk of developing blood clots, and at the same time it increases the risk of embryonic arrest, which has an impact on the pregnant woman to the fetus. In normal people, if there is difficulty in breathing or severe cough or shortness of breath, and the cause is unknown, it is necessary to take a lung CT and do ECG examination in time, and if there is any abnormality, it is necessary to further test D-dimer in time, and the comprehensive overall examination has some significance in diagnosing pulmonary embolism.