Health Centres - Anaemia due to iron deficiency
What is anaemia?
You get anaemia when you don't have enough red blood cells. This makes it difficult for your blood to carry oxygen, causing unusual tiredness and other symptoms.
The number of red blood cells can drop if there is:
- a reduction in the number of red blood cells produced
- an increase in the loss of red blood cells.
Vein: takes blood back to the heart.
Red blood cells and oxygen
The red blood cells take up oxygen in the lungs and carry it to all the body's cells. Your cells use this oxygen to fuel the combustion (burning) of sugar and fat which produces the body's energy.
During this process carbon dioxide is created as a waste product. It binds itself to the red blood cells that have delivered the oxygen.
The red blood cells then transport the carbon dioxide back to the lungs. We exchange this carbon dioxide for fresh oxygen by breathing.
This process is called oxidation.
Why does a lack of iron cause anaemia?
The body needs iron, vitamin B12 and folic acid (one of the B group of vitamins) to produce more red blood cells. If there is a lack of one or more of these nutrients, anaemia will develop.
Iron deficiency anaemia is the most common type of anaemia. In the UK 8 per cent of women have this type of anaemia.
Iron deficiency is more frequent in women who smoke, eat a diet low in iron and have heavy periods.
What causes this type of anaemia?
In adults the most common cause is losing blood faster than the body can replace it.
- A lack of iron in the diet is common in vegans and vegetarians because the main dietary source is red meat.
Through its pumping action, the heart propels blood around the body through the arteries.
Red blood cells are made in the bone marrow and circulate in the blood. They only have a life expectancy of about four months.
Most childhood cases are caused by a poor diet that contains little iron.
- Babies can develop iron deficiency, especially if they are premature. Storing iron is not usually completed until the final stages of pregnancy.
- The body needs more iron when a large amount of cell divisions occur, such as in pregnancy and during periods of rapid childhood growth.
- Loss of blood through heavy menstruation can deplete iron stores.
- Diseases of the small intestine such as gluten intolerance (coeliac disease) and Crohn's disease (inflammation of the intestine) can reduce its ability to absorb iron.
- If there seems to be no cause for the iron deficiency, consult your doctor. Less commonly, small ruptures in the intestine due to cancer or polyps (small growths), and ulcers in the stomach and small intestine can cause iron deficiency anaemia.

