The kidneys are bean-shaped organs that are located near the middle of the back, just below the rib cage with one on each side of the spine. Kidneys are responsible for many essential regulatory roles, including filtering the blood to keep it clean and chemically balanced; production of a hormone called erythropoietin. One of the most important is the removal of waste products from the blood, which comes from food and the normal breakdown of active tissues, such as muscles.

The kidneys also produce hormones that support the function of other organs in the body, including hormones erythropoietin that supports the production of healthy red blood cells.