The severity of polycystic kidney is mainly judged by relevant examinations, common renal concentrating function, blood creatinine, proteinuria, ultrasound and other examinations. 1. Renal concentrating function: manifested as polyuria and nocturia, but to a lesser extent. It can be manifested at an earlier stage. Salt-loss nephritis can be manifested in the late stage. The dilution and acidification function of the kidney is generally unimpaired. 2. Blood creatinine: blood creatinine indicates the loss of renal compensatory ability, the higher the blood creatinine rises, the more serious polycystic kidney. 3. Proteinuria: If there is a large amount of proteinuria, it often suggests the combination of other glomerular diseases. Proteinuria and microalbuminuria are independent risk factors for renal failure in polycystic kidney. 4. Ultrasonography: the more dark areas in both kidneys and the faster the cysts increase in size, the more serious the polycystic kidney is. The severity of polycystic kidney is mostly based on the relevant examination, under the guidance of doctors, so when polycystic kidney should be early regular hospital consultation, standardized treatment under the guidance of physicians.