Defined as a reduction in the absolute number of circulating red blood cells and most commonly diagnosed when the haemoglobin (Hb) concentration is reduced below the reference range for age and gender. The clinical features depend on the severity of anaemia, the rate at which it developed and the oxygen demands of the patient.
Cause
Can be classified according to the mean corpuscular volume (MCV) of the red blood cell (RBC) into macrocytic anaemia (MCV>100 fL); microcytic anaemia (MCV < 80 fL) or normocytic anaemia (MCV 80 - 100 fL).