The diagnosis of diabetic nephropathy primarily relies on the clinical symptoms and medical history of the patient. Such patients often exhibit proteinuria, sometimes even severe proteinuria, and may also experience renal failure. Additionally, these patients have a history of diabetes, usually extending over ten years, followed by renal damage, and often accompanied by diabetic retinopathy. In such cases, a preliminary diagnosis can be made based on clinical features. However, there is still a risk of misdiagnosis, as the proteinuria could also be caused by other diseases affecting the glomeruli. Therefore, to confirm the diagnosis, it is best to conduct a renal biopsy, which can provide a definitive diagnosis.