The reasons for the high dimer measurement are as follows: 1. Poly-epidemic fibrinolytic hyperfunction: such as hypercoagulable state, diffuse intravascular coagulation, renal disease, rejection of organ transplantation, thrombolytic therapy, etc.; 2. Other: myocardial infarction, cerebral infarction, pulmonary embolism, venous thrombosis, surgery, tumor, diffuse intravascular coagulation, infection and tissue necrosis, etc. Dimer mainly refers to D-dimer, which is a degradation product of fibrin. The human body contains fibrinolytic enzymes, and the inhibiting enzymes maintain a dynamic balance and inhibit each other, so that blood flows normally in the blood vessels and no clotting or thrombosis occurs. When coagulation or thrombosis occurs due to abnormal factors, the fibrinolytic system in the body is activated, degrading fibrin to form fragments, which are connected by D-dimers, thus D-dimer is a sensitive marker of acute thrombosis. D-dimer is derived from cross-linked fibrin clots lysed by fibrinolytic enzymes and mainly reflects the fibrinolytic function, therefore, D-dimer is mainly used in the diagnosis of venous thromboembolism, renal vein thrombosis and pulmonary embolism.