The role of red blood cells is to take up the oxygen breathed in through the lungs and to transport it to the tissues. The body needs oxygen to burn food and release energy. When the red cell count is below normal, the tissues receive insufficient oxygen and the body is constantly short of energy.

Anaemia markedly impairs physical well-being. People with anaemia suffer from constant tiredness, exhaustion on mild exertion such as climbing stairs, cold extremities, pale skin and listlessness.