Anaemia is a deficiency in the number or quality of red blood cells. Lack of iron is common in anaemic people. Symptoms include tiredness, breathlessness and pale skin. Treatment may include iron supplements. Pernicious anaemia may require injections of vitamin B12.

Anaemia is a deficiency in the number or quality of red blood cells. The red blood cells carry oxygen around the body, using a particular protein called haemoglobin. Anaemia means that either the level of red blood cells or the level of haemoglobin is lower than normal.

When a person is anaemic, their heart has to work harder to pump the quantity of blood needed to get adequate oxygen around their body. During heavy exercise, the cells may not be able to carry enough oxygen to meet the body’s needs and the person can become exhausted.

Anaemia isn’t a disease in itself, but a result of a malfunction somewhere in the body. This blood condition is common, particularly in females. Some estimates suggest that around one in five menstruating women and half of all pregnant women are anaemic.

Red blood cells explained

Blood cells are produced in the bone marrow. You need certain nutrients in your diet to make and maintain red blood cells. Each red blood cell contains a protein called haemoglobin. This protein gives red blood cells their characteristic colour.

Oxygen molecules attach themselves to haemoglobin. The body’s cells need oxygen to live and perform their various duties.

The bone marrow needs enough dietary iron and some vitamins to manufacture haemoglobin. If you don’t have enough iron in your diet, the body will draw on the small reserves of iron stored in your liver. Once this reservoir is depleted, the red blood cells will not be able to carry oxygen around the body effectively.
Causes of anaemia

Anaemia can have many causes, including:

  • Dietary deficiency – lack of iron, vitamin B12 or folic acid in the diet.
  • Malabsorption – where the body is not able to use the nutrients in the diet, caused by conditions such as coeliac disease.
  • Inherited disorders – such as thalassaemia or sickle cell disease.
  • Autoimmune disorders – such as autoimmune haemolytic anaemia, where the immune cells attack the red blood cells and decrease their life span.
  • Chronic diseases – such as rheumatoid arthritis and tuberculosis.
  • Hormone disorders – such as hypothyroidism.
  • Bone marrow disorders – such as cancer or infection.
  • Blood loss – due to trauma, surgery, cancer, peptic ulcer, heavy menstruation, bowel cancer or frequent blood donations.
  • Drugs and medications – including alcohol, antibiotics, anti-inflammatory drugs or anti-coagulant medications.
  • Infection – such as malaria and septicaemia, which reduce the life span of red blood cells.
  • Periods of rapid growth or high energy requirements – such as puberty or pregnancy.