Anemia is the deficiency of red blood cells or of hemoglobin in the blood. The World Health Organization (WHO) defines anemia as a hemoglobin concentration lower than 13.0 g/dl in men and postmenopausal women, and 12.0 g/dl in other women. thirteen grams per deciliter in men and postmenopausal women, and twelve grams per deciliter in other women.

Deficiency of erythropoietin is the primary cause of anemia associated with chronic kidney disease. Other causes of anemia in chronic kidney disease are blood loss, shortened red cell life span, uremic milieu, iron deficiency and inflammation. Recombinant erythropoietin (rhEPO) is administered to chronic disease patients to treat anemia.