The kidneys are a pair of organs that filter waste materials out of the blood. The waste is passed out out of the body as urine. Kidneys produce important hormones and regulate blood pressure and the levels of water, salts, and minerals in the body. Kidney damage can occur in someone who has had diabetes for many years, especially if the diabetes isn't controlled. You'll find your kidneys on either side of your spine, just below the rib cage.