How does anemia develop in patients with chronic renal failure?

Anemia in patients with chronic kidney disease is due to the decreased renal (i.e by the kidneys) production of the hormone, erythropoietin. Erythropoietin is needed to stimulate the production of red cells by the bone marrow. Lack of erythropoietin causes decreased red blood cell production, recognized as anemia. Synthetic erythropoietin is now available to correct the anemia.