The various types of anaemia (renal anaemia, bleeding, other types of deficiency anaemias, anaemia caused by other diseases) differ in their cause. They can be due to inadequate red blood cell production in the bone marrow, premature red blood cell breakdown, acute or chronic bleeding or defective haemoglobin.

Anaemia occurs when the number of erythrocytes, the oxygen carriers of the blood, is considerably below normal. The red blood cell count is normally above 3.9 million/µl in women and about 4.3 million/µl in men.

In renal anaemia the chronically diseased kidney produces too little erythropoietin – a vital hormone that stimulates red blood cell production in the bone marrow. As a result, maturation of new red blood cells in the bone marrow begins to falter, impairing the body’s oxygen supply. Over 90% of patients with chronic kidney disease suffer from renal anaemia.