Diabetic nephropathy is caused by long-term diabetes leading to damage in the small blood vessels. Generally, patients have a history of diabetes for over ten years. Diabetic nephropathy progresses through several stages. In the early stages, patients primarily exhibit microalbuminuria. Due to the presence of protein in the urine, patients may experience increased urine foam, especially noticeable with morning urination. Some patients may develop swelling in the lower limbs and around the eyelids. As the condition progresses, the amount of urine protein increases and the swelling becomes more pronounced, potentially reaching the level of nephrotic syndrome.