Patients with diabetic nephropathy actually have an irreversible condition. If a patient has developed mild to moderate proteinuria and entered stage three, it's generally because of long-term high blood sugar, oxidative stress, and an excess of glycation end products damaging the capillaries of the glomerulus, resulting in increased permeability and the occurrence of proteinuria. The damage that has already occurred cannot be reversed; however, patients still need active treatment to control their blood sugar and blood pressure in order to slow down the progression of diabetic nephropathy as much as possible. Stage three diabetic nephropathy is incurable, but treatment can slow the progression of the kidney disease, preventing the development from microalbuminuria to macroalbuminuria. Stage three refers to the early period of diabetic nephropathy, typically seen in diabetic patients who have had the disease for more than five years. It can feature a continuous increase in urinary albumin excretion rates. High filtration rates and long-term poor metabolic control may be reasons for the persistent microalbuminuria. During this stage, patients may experience a mild increase in blood pressure, and reducing blood pressure can decrease the excretion of microalbumin. During this period, strict control of blood sugar is necessary. Oral hypoglycemic drugs can be used for treatment, and it's crucial to regularly monitor fasting blood glucose, postprandial blood glucose, and glycated hemoglobin. Blood pressure should also be actively controlled, generally targeting a value of 130/80mmHg. Angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists are preferred as they can lower blood pressure, reduce proteinuria, and have a protective effect on the kidneys, thus delaying the progression of kidney disease.