Iron deficiency anaemia

This information from Great Ormond Street Hospital (GOSH) is about iron deficiency anaemia – a special type of anaemia caused by a lack of the mineral iron in the body.

Anaemia is a very common condition which can leave you feeling tired, weak and lacking in energy. It’s where someone has fewer red blood cells, or less haemoglobin in their red blood cells than normal. Haemoglobin is the substance which makes your blood red and carries oxygen around your body. Iron is important for forming haemoglobin, so a reduced iron level causes a reduced haemoglobin level in your blood.


Iron deficiency anaemia is the most common form of anaemia. Iron can be found in many foods that we eat, like red meat, fish and leafy green vegetables. If your diet doesn’t contain enough of these foods, you can develop iron deficiency anaemia.

It can also be caused if your body doesn’t absorb iron from the food that you eat. For example, this can occur if you drink a lot of cow’s milk as this blocks iron absorption. It can also develop because of long-term blood loss. Some girls may experience this when they start to have periods if they can’t replace the iron lost during this time.


If someone has mild anaemia, you may not show any symptoms at all, but common signs and symptoms include pale skin, lack of energy and breathlessness.

If anaemia becomes more severe, it can be life threatening, so it's important to see your doctor if you think you might have the symptoms.


Iron deficiency anaemia is usually diagnosed using blood tests. A doctor will take a small sample of blood and send it to a laboratory. The test will count the number of each type of blood cell present in the sample (full blood count) and then check how much haemoglobin is contained in the red blood cells.

They may also carry out other tests to see how much iron is contained in the haemoglobin. All of these test results provide information about whether anaemia is present and if so, how severe it is.

If someone has anaemia, they may need further tests to work out what’s causing it if iron deficiency anaemia is unlikely. Rarely, they may need to have a sample of bone marrow taken to see if red blood cells are forming as they should.


The most common treatment is a course of iron tablets or liquid to be taken by mouth. Although iron is best absorbed on an empty stomach, taking it this way can sometimes make people feel a bit sick. This can be prevented by taking it with some food and vitamin C (for example in orange juice) which increases the absorption. Iron absorption is reduced by milk, tea, coffee and certain medicines, which should not be taken at the same time. If you are taking iron supplements people will have black stools (poo). This is normal.

There are ways to increase the amount of iron in the diet as well as medication. Foods rich in iron include:

  • meat
  • beans and lentils
  • eggs
  • fish
  • apricots, prunes and raisins
  • leafy green vegetables
  • oatmeal
  • tuna
Eating fortified cereal is also a useful way of boosting iron intake. If you have any questions about how to improve your iron intake, you could ask your doctor for a referral to a dietitian either in your local community or at your local hospital.

Looking ahead

Iron deficiency anaemia is usually short-lived with haemoglobin levels usually returning to normal within a month or two. Doctors will usually advise people to continue to take iron medication for a few more months to make sure that blood levels remain stable and the body builds up a ‘store’ of iron for the future.

Last review date:
July 2014