A type of anaemia caused by inadequate levels of iron in the body
Iron-deficiency anaemia is the most common form of anaemia (a deficiency of the oxygen-carrying pigment haemoglobin in red blood cells). Iron is an essential component of haemoglobin in the production of blood. If insufficient iron is available, the production of haemoglobin and its incorporation into red blood cells in the bone marrow are reduced. As a result, there is less haemoglobin to bind with oxygen in the lungs and to carry the oxygen to the tissues of the body. Consequently, the tissues may receive insufficient oxygen.
Iron-deficiency anaemia is most commonly caused by the loss of significant quantities of iron through persistent bleeding. This type of anaemia mainly affects women who experience regular blood loss over a period of time from heavy menstrual bleeding (see Menorrhagia). Persistent loss of blood may also be due to stomach ulcers (see Peptic ulcer). Prolonged use of aspirin or long-term use of nonsteroidal anti-inflammatory drugs is a possible cause of bleeding from the lining of the stomach. In people over the age of 60, a common cause of blood loss is cancer of the bowel (see Colorectal cancer). Bleeding in the stomach or in the upper intestine may go unnoticed, while blood lost from the lower part of the intestine or the rectum may be visible in the faeces.
The second cause of iron-deficiency anaemia is insufficient iron in the diet. People whose diet contains little or no iron, such as vegans, may be at particular risk of developing the condition.
Iron-deficiency anaemia is also more likely to develop when the body needs higher levels of iron than normal and these extra demands are not met by the existing diet. For example, children who are growing rapidly, especially adolescents, and women who are pregnant have an increased risk of developing iron-deficiency anaemia if their diet does not contain plenty of iron.
Some other causes of iron-deficiency anaemia include disorders that prevent absorption of iron from the diet. In the body, iron is absorbed from food as it passes through the small intestine; conditions that cause damage to the small intestine, such as coeliac disease or surgery on the small intestine, sometimes result in iron deficiency.
In addition to any specific symptoms associated with an underlying disorder, you may experience the general symptoms of anaemia, which include:
Tiredness and a feeling of faintness.
Shortness of breath on mild exertion.
You may also have symptoms that are due to a marked deficiency of iron:
Brittle, concave-shaped nails.
Painful cracks in the skin at the sides of the mouth.
A smooth, reddened tongue.
If your anaemia is severe, you may be at risk of chronic heart failure because your heart has to work harder to supply blood to the rest of the body.
Your doctor will arrange for blood tests to measure the levels of haemoglobin and iron in your blood. If the cause of the iron deficiency is not obvious, other tests may be arranged to look for evidence of internal bleeding. These tests may include upper digestive tract endoscopy and colonoscopy.
If there is an underlying disorder, this will be treated. Your doctor may prescribe iron tablets (syrup for children) or, less commonly, iron injections to replace iron stores (see Minerals). Your doctor may also recommend vitamin C (abundant in citrus fruits and citrus fruit juices) with meals because this vitamin aids absorption of iron. Severe anaemia may require blood transfusion.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.