Elevated D-dimer is mainly seen in hypercoagulable states of the blood and can be seen in myocardial infarction, cerebral infarction, pulmonary embolism, disseminated intravascular coagulation in tumors, thrombolysis, infections, and tissue necrosis. Under normal circumstances, the D-dimer value may be less than 0.3 mg/l or less than 0.5 mg/l depending on the reagent used. Since each hospital uses different reagents, the test values may not be exactly the same. D-dimer is a product of thrombolysis and is used clinically to assess whether embolization has occurred. This indicator is only used as an auxiliary diagnostic indicator. If a patient is suspected of having a thrombotic disease, the diagnosis needs to be based on the clinical manifestations and other examination results, and timely medication and surgical treatments need to be given. If this index is found to be elevated in the clinic, it is necessary to consult the doctor in time and follow the doctor’s instructions to standardize the treatment.