N25-N29: Other disorders of kidney and ureter

N26: Unspecified contracted kidney

There are normally 2 kidneys in the body. They filter blood and create urine. They thus help to detoxify the body. Furthermore, the kidneys regulate the blood pressure and salt content in the blood, among other things.

If a kidney is damaged, perhaps by a disease, it may become smaller. A kidney that is too small often stops working properly. If just one kidney stops working properly, the healthy kidney can often take over completely.