The kidney volume increases, and the harm to the human body needs to be evaluated after clarifying the cause of the increase in kidney volume.1. Compensatory enlargement of the kidney. If a patient’s one kidney is removed due to disease, or one kidney is traumatized, or one kidney is atrophied, etc., the kidney on the opposite side will have compensatory enlargement, and the purpose of kidney enlargement at this time is to maintain the human water and electrolyte metabolic balance. This enlargement is a physiological regulatory enlargement, which is not harmful to the human body.2. When various diseases occur in the kidney, there can be an increase in size. For example, if the kidney grows benign or malignant tumor, the kidney volume will increase. At this time, the tumor will destroy the original normal tissues of the kidney and cause renal insufficiency and bleeding, which may affect the life and health of patients in serious cases and need to be removed surgically. If extra-renal factors lead to obstruction and fluid accumulation in the kidney, it may also increase in size. Such as ureteral stones, ureteral occupancy or ureteral stenosis can cause the urine produced by the kidney to be unable to drain out of the kidney in time, and fluid accumulation in the kidney can occur. At this time, the kidney volume increases, and if left untreated for a long time, it can lead to edema and back pain in patients, which can cause secondary renal insufficiency and renal failure.