A D-dimer above 0.2 mg/L suggests the possibility of a tumor, but the presence of a tumor cannot be determined by the D-dimer value; pathology is needed to ultimately confirm the presence of a tumor and to determine the type of tumor. Elevated D-dimer usually indicates that the blood is in a hypercoagulable state. Tumor cells can cause the release of procoagulant substances into the bloodstream, resulting in hypercoagulability, which can lead to coagulation or blood clots, and elevated D-dimer can also indicate deep vein thrombosis, pulmonary embolism, and severe infections. Further testing is needed to confirm the diagnosis. Therefore, elevated D-dimer is not a specific indicator for the diagnosis of tumors. If patients have elevated D-dimer, they should consult a doctor in time to improve relevant examinations and carry out treatment under the guidance of the doctor.