The main reasons for the increase in kidney volume are: 1. If one side of the kidney is atrophied or functionally incompetent, the other side of the kidney may increase compensatory, and this type of patients often only have a unilateral increase in kidney volume. 2. The presence of ureteral blockage and stenosis can lead to hydronephrosis, and at this time the kidney volume will increase. 3. The kidney volume will increase due to acute glomerulonephritis, early diabetic nephropathy and renal amyloidosis, etc. This is often a bilateral increase in kidney volume. 4. Tumors and occupancies in the kidney will also cause an increase in volume. Therefore, if the kidney volume increases, we should improve the related examination to further clarify the cause of the kidney volume increase.