Generally speaking, diabetic nephropathy does not cause hematuria. The main site of damage in diabetic nephropathy is indeed the glomerulus. Prolonged hyperglycemia and metabolic disorders can lead to damage to the capillaries of the glomerulus. However, the main clinical characteristic of this damage is proteinuria, which causes glomerulosclerosis and may also lead to renal failure, but it is rare for patients to have red blood cells in their urine or to experience hematuria. Therefore, if a patient with diabetic nephropathy has visible hematuria, such as red or tea-colored urine, it is necessary to check for other causes beyond diabetes, such as urinary tract infections, urogenital system stones, tumors, etc., all of which can cause hematuria.