In the first stage of diabetic nephropathy, there are no obvious symptoms, but renal function tests can reveal an increased glomerular filtration rate. In the second stage, the patient still has no obvious symptoms appearing, the urinary protein excretion rate is normal at rest, i.e. <20 micrograms/minute, and the urinary albumin excretion rate increases during stressful conditions such as exercise. During this period, the patient's glomerular filtration rate may remain high or fall to normal. Early glomerular lesions can be detected if a renal biopsy is performed. In the third stage, also known as early diabetic nephropathy, the patient begins to show significant abnormalities from this stage. At this stage, the glomerular filtration rate is approximately normal and hypertension begins to develop. Once diabetic nephropathy has progressed to this stage, the nephropathy is irreversible. The fourth stage is the clinical nephropathy stage, the main characteristics of this stage are large amount of proteinuria, urine protein excretion rate >3.5 g/day, positive urine routine protein, patients can find the typical proteinuria performance when urinating, that is, the urine foam is many, and the foam can not dissipate for a long time. In addition, the patient presents with hypertension and swelling. The last stage, which is the fifth stage, is the renal failure stage, which is also often called end-stage renal disease in clinical practice. Starting from the appearance of large amounts of proteinuria, the kidney function of the patient deteriorates faster until renal failure. In this stage, the amount of urine protein does not decrease, and patients show significant hypertension and swelling, as well as anemia, and because patients with advanced diabetic nephropathy are often malnourished, they are more likely to develop other complications, such as retinopathy.