Low glycosylated hemoglobin may be due to changes in the processes of erythropoiesis, erythrocyte destruction, glycation process, and structural changes in hemoglobin. 1. Erythropoiesis: usually the presence of iron, vitamin B12, erythropoietin medication history of the patient will lead to low glycosylated hemoglobin. Chronic liver disease and reticulocytosis may also induce low glycosylated hemoglobin. 2. Destruction of red blood cells: shortening of the life span of red blood cells, antiretroviral drugs, certain hemoglobin disorders, splenomegaly, rheumatoid arthritis and other conditions can also lead to low glycosylated hemoglobin. 3. Glycation process: low glycosylated hemoglobin may also be associated with aspirin, vitamin C and vitamin E, elevated intraerythrocytic PH, and certain hemoglobinopathies. 4. Hemoglobin structural changes: usually hemoglobin genetic or chemical changes in the case of hemoglobin, such as hemoglobinopathies, methyl hemoglobin, etc., but also can increase or decrease the glycated hemoglobin. It is recommended that patients with low glycosylated hemoglobin take systematic treatment under medical evaluation.