High D-dimer may be caused by pregnancy, chronic kidney disease, pulmonary embolism, etc. 1. Pregnancy: High D-dimer mainly refers to hypercoagulable state of blood vessels, disseminated coagulation causing thrombosis or hypercoagulability. Due to the change of hormone level in pregnant women during pregnancy, it may lead to the expansion of blood vessels, slow down the blood flow, thus the blood is in a state of hypercoagulability, which may cause the situation of high D-dimer. 2. Chronic kidney disease: Chronic kidney disease will lead to a decrease in the amount of albumin in the blood, and the increase in blood viscosity may lead to platelet aggregation and hypercoagulability, thus causing high D-dimer. 3. Pulmonary embolism: when there are fractures, trauma, tumors and other diseases, may lead to patients with slow blood flow, the emergence of deep vein thrombosis of the lower extremities caused by pulmonary embolism, when the thrombus is formed, may lead to D-dimer concentration increases. Patients with high dimerization are recommended to go to the hospital for relevant examinations in time to clarify the cause of the disease and then follow the doctor’s instructions for treatment.