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UC Davis Transplant Center

UC Davis Transplant Center

The Kidneys: What do they do?

The kidneys are bean shaped organs about the size of an adult fist. Most people are born with two kidneys. They are located on each side of the backbone, against the back wall of the abdomen, at about the level of the lowest rib.

The kidneys do many things to keep your body healthy and in a state of balance.  The primary function of the kidneys is to regulate the fluid environment in the body.  This is done through the formation of urine.  By making urine, the kidneys are able to:

  • Regulate blood volume by removing excess fluid from the body
  • Regulate blood pressure
  • Filter out waste products of metabolism
  • Maintain the body's chemical balance
  • Maintain the proper pH of the blood
  • Help regulate red blood cell production

The renal arteries carry blood to the kidneys. The kidneys are the organs that filter the blood, regulate volume and blood pressure and make urine.  The renal veins return blood from the kidneys back to the main circulation.  The ureters are tubes that carry the urine from the kidneys to the bladder.  The bladder is simply the "tank" that stores urine until you go to the bathroom.