Hi airtas.
Early stages of diminished kidney function are generally asymptomatic; this means there are little or no symptoms in the beginning stages of Diabetic Nephropathy. Symptoms will usually occur after the kidneys have been damaged.
The best detection is through laboratory testing. Mild to moderate renal insufficiency is characterized by elevated BUN (blood, urea, nitrogen) and creatinine levels. Nocturia (night urination) is common due to a failure to concentrate urine while sleeping. Fatigue, lassitude, pallor, anemia, swelling and cramping of the legs, and high B/P are all prominent features of nephropathy. Abnormal electrolyte values (Na, K, CO2, CL) can also be indicative of kidney failure.
Hope that helps
Shy