Iron deficiency anaemia

Published by Bupa’s Health Information Team, December 2011.

This factsheet is for people who have iron deficiency anaemia, or who would like information about it including symptoms, causes and treatments.

Iron deficiency anaemia is a type of anaemia caused by not having enough iron in your body. Anaemia is a condition in which the blood can’t carry enough oxygen to meet the needs of your body.

About iron deficiency anaemia

You need iron for many important processes inside your body. It’s especially important for making haemoglobin – the protein in your blood that carries oxygen.

Iron is absorbed from your food and drink by your bowel. It’s carried in your blood to your bone marrow, where blood cells are produced. Here, the iron is combined with proteins to make haemoglobin. Any iron that doesn’t get used up is stored in the bone marrow and other organs, such as your liver.

If you don’t have enough iron, your body can’t make enough haemoglobin to meet its needs. Your red blood cells then become abnormally small and can’t carry enough oxygen to your organs and tissues. This leads to the symptoms of anaemia.

Babies, teenagers and women who have heavy periods are more likely to get iron deficiency anaemia.

Symptoms of iron deficiency anaemia

Common symptoms of all types of anaemia include:

  • feeling tired
  • looking pale
  • increased breathlessness
  • feeling your heart racing or thumping (called palpitations)

If you have iron deficiency anaemia, you may also develop other problems, such as:

  • brittle nails
  • mouth sores or ulcers
  • difficulty swallowing

These symptoms may be caused by problems other than iron deficiency anaemia. If you have any of these symptoms, see your GP.

Complications of iron deficiency anaemia

If you have anaemia, your heart has to work harder to get oxygen to your vital organs. If left untreated it can lead to problems with your heart and lungs. In the short term, iron deficiency can affect your ability to work and exercise.

Causes of iron deficiency anaemia

There are a number of causes of iron deficiency anaemia. Some of the most common are listed below.

Blood loss

This is the most common cause of iron deficiency anaemia and includes:

  • heavy menstrual bleeding (if you’re a woman)
  • bleeding in your stomach or bowel from an ulcer or cancerous growth
  • bleeding caused by medicines, such as aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs)
  • an injury or a surgical operation associated with heavy blood loss
  • bleeding from a hookworm infection, but this usually only affects people in tropical countries

Poor diet or digestion

If you don’t get enough iron in your diet, or if it isn’t absorbed properly, you can develop iron deficiency anaemia. This can happen, for example, if you:

  • don’t eat iron-rich foods, such as meat
  • have a bowel disorder, such as coeliac disease or Crohn's disease
  • have had stomach surgery (especially if you have had a part of it removed)

Other causes

If your body has a sudden demand for extra iron, you may develop iron deficiency anaemia. This can happen, for example, if you have a growth spurt (which is most common during the teenage years) and your body makes more red blood cells to support your developing bones, muscles and tissues. It can also happen if you're a woman and become pregnant, because your body will need more iron to meet the needs of your developing baby.

Diagnosis of iron deficiency anaemia

Your GP will ask about your symptoms and examine you. He or she may also ask about your medical history. If your GP suspects you have anaemia, you will be asked to have a blood test. Your blood will be sent to a laboratory and tested for the following. 

  • A full blood count. This is to check the level of haemoglobin in your blood, how many of each of the different types of blood cell you have, the size of your red cells, and the amount of haemoglobin in each red cell.
  • A blood film. This involves looking at your blood under a microscope to check the size and shape of your red blood cells and to assess the different white cells that are present.
  • Serum iron, iron binding capacity and ferritin. The levels of each of these will be measured.

If the blood tests show that you have low levels of haemoglobin with small, pale, red cells, you may have iron deficiency anaemia. This can be confirmed if you also have low levels of ferritin in your blood.

You may need to have further tests to help identify the cause of your iron deficiency. Your GP may refer you to a haematologist (a doctor who specialises in identifying and treating conditions of the blood) or a gastroenterologist (a doctor who specialises in identifying and treating conditions that affect the digestive system). If you’re a woman, your GP may refer you to a gynaecologist (a doctor who specialises in women’s reproductive health).

Treatment of iron deficiency anaemia

Treatment involves replacing iron in your body. If a particular condition is causing the iron deficiency, you may also need to have other treatments. 


If you don’t get enough iron, your GP will give you advice on how to change your diet, or refer you to a dietitian.


Taking iron tablets is the best way to make up for the shortage of iron in your body. Your GP may recommend you take iron tablets two or three times a day for up to six months.

Iron tablets can cause side-effects, such as feeling sick, heartburn, constipation and diarrhoea. You can reduce your risk of getting these by taking the tablets after meals and drinking enough fluids. Always read the patient information leaflet that comes with your tablets and if you have any questions, ask your GP or pharmacist for advice.

If you’re unable to take iron tablets, or if they don’t work, your GP may suggest you have an iron infusion through a drip into a vein. Iron infusions can cause side-effects, such as headache or joint pains and, occasionally, allergic reactions. Alternatively, you may be able to have iron injections. However, these aren’t used very often as they can be painful and may stain your skin.

Hospital treatment

If you have severe anaemia, you may need to have a blood transfusion. This is when red blood cells are given straight into your bloodstream through a small tube (cannula) put into a vein, usually in your arm.

Prevention of iron deficiency anaemia

You can reduce your risk of developing iron deficiency anaemia by eating a healthy, balanced diet that contains plenty of iron-rich foods. For most people this will provide enough iron without the need to take supplements.

A healthy diet that includes red meat, green vegetables, dried fruit, chick peas, lentils and fortified foods (those that have particular nutrients added during manufacturing), such as breakfast cereals and bread, should contain all the iron you need.


For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.

  • This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.

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  • Publication date: December 2011

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