Increased D-dimer suggests the possible presence of thrombophilia from a variety of causes. D-dimer is a specific marker of the fibrinolytic process, mainly reflecting fibrinolytic function.D-dimer is a negative exclusion test, a non-invasive means of examination, which is valuable in the exclusion of diagnosis of acute pulmonary embolism, deep vein embolism, disseminated intravascular coagulation and other diseases. Clinically, D-dimer is elevated whenever there is activated thrombosis and fibrinolytic activity in the body’s vasculature, such as acute cerebral infarction, acute pulmonary embolism, disseminated intravascular coagulation, acute venous thrombosis, burns, surgery, trauma and sepsis. Elevated D-dimer in any case can not simply be used as the only basis for the diagnosis of acute pulmonary embolism, deep vein embolism, disseminated intravascular coagulation, and can not indicate the cause and location of thrombosis, but must be analyzed in conjunction with the clinical situation. It is recommended to consult a doctor in case of any situation.