Human kidneys derive their name from their unique shape. The bi-lateral organ structures are kidney bean-shaped, and are located at the back of the abdominal cavity (retroperitoneal). In most adults they are small--about the size of the average adult fist--but this size is not indicative of their importance. The kidney's role in the body's chemistry and operation is absolutely vital to life.

An estimated 1,000 milliliters (mL) of fluid flows through the kidneys each minute. The water that is reconditioned by the kidneys is responsible for maintaining the proper balance of acid and base and of ions (such as sodium and potassium) in cellular and tissue fluids and in blood plasma. Kidneys also keep the volume of water in the body constant, help regulate blood pressure, and stimulate the production of red blood cells via hormone signals. Abnormalities in the ionic balances can cause functional disruption to organs, specialized...