Remove waste. The kidneys filter waste products
and excess fluid out of the blood and remove them from the body in the form of
urine. Waste products and excess fluid are produced by the normal breakdown of
food and the chemical reactions that occur in cells throughout the body
(metabolism). Filtering waste products is the most important function of the
Keep the right balance of chemicals in the body. The
kidneys keep the right balance of chemicals, such as sodium, potassium,
calcium, magnesium, and other substances your body needs to function properly.
They filter excess amounts of these chemicals from the blood and get rid of
them in the urine.
Make hormones. The kidneys produce three
important hormones: renin, erythropoietin, and the active form of vitamin D.
Renin helps regulate blood pressure. Erythropoietin is needed to make red blood
cells. Your body needs the active form of vitamin D to absorb calcium from
food. Together, vitamin D and calcium help build healthy bones and maintain
normal muscle function.
Primary Medical Reviewer
Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer
Tushar J. Vachharajani, MD, FASN, FACP - Nephrology
How this information was developed to help you make better health decisions.