What is anaemia?

Anaemia is a deficiency of red blood cells, which can lead to a lack of oxygen-carrying ability, causing unusual tiredness and other symptoms.

The deficiency occurs either through the reduced production or an increased loss of red blood cells. These cells are manufactured in the bone marrow and have a life expectancy of approximately four months.

To produce red blood cells, the body needs (among other things) iron, vitamin B12 and folic acid. If there is a lack of one or more of these ingredients anaemia will develop.

What are red blood cells?

Red blood cells are made in the bone marrow and circulate in the blood. Through its pumping action, the heart propels the blood around the body through the arteries. The red blood cells obtain oxygen in the lungs and carry it to all the body's cells.

The cells use the oxygen to fuel the combustion (burning) of sugar and fat which produces the body's energy.

During this process called oxidation, carbon dioxide is created as a waste product. It binds itself to the red blood cells that have delivered their load of oxygen. The carbon dioxide is then transported back to the lungs where it is exchanged for fresh oxygen by breathing.

What causes iron deficiency?

Most cases of iron deficiency in children are caused by eating a poor diet containing little iron. In adults, however it is most commonly caused by losing blood faster than the body can remake it.

A lack of iron in the diet is common in vegetarians because the main general dietary source is red meat. Babies can develop iron deficiency, especially if they have been born prematurely. Their storage of iron is usually not completed until the final stages of pregnancy.

An increased need for iron arises when a large amount of cell divisions occur, such as during pregnancy, and during periods of rapid childhood growth.

Reduced absorption from the intestine of iron can be caused by diseases of the small intestine such as gluten intolerance (coeliac sprue) or Crohn's disease (inflammation of the intestine).

Always consult a doctor for unexplained iron deficiency. The cause could be small ruptures in the intestine due to cancer or polyps (small growths). Ulcers in the stomach and duodenum can also lead to iron deficiency anaemia. This loss of blood from the digestive tract may be so slight as to be undetected on its own.

Iron deficiency is more frequent in women who smoke, eat a diet low in iron and have heavy periods.

What are the symptoms of anaemia due to iron deficiency?

• If a person is otherwise healthy, symptoms seldom appear before the haemoglobin (red pigment) drops below 10g/dl.
•  The first symptoms will be tiredness and palpitations (awareness of the heartbeat).
• Shortness of breath and dizziness is common.
• If the anaemia is severe, angina (chest pain), headache and leg pains (intermittent claudication) can occur.

Besides the general symptoms of anaemia there will be unique symptoms in pronounced and long-term cases of iron deficiency. These will be especially noticeable in the tongue and throat and include:

• a burning sensation in the tongue.
• dryness in the mouth and throat.
• sores at the corners of the mouth.
• an altered sense of touch.
• a smooth tongue.
• in extreme cases the nails can become brittle and spoon shaped with vertical stripes and a tendency to fray.
• or a 'pica' can arise - an insatiable craving for a specific food, eg liquorice.
• brittle hair.
• difficulty in swallowing.

Possible deterioration

Shortness of breath, palpitation and angina.

Iron deficiency can in rare cases cause permanent changes to the mucosa (soft lining) in the throat (Plummer-Vinson syndrome). This condition is a preliminary stage to cancer.

How does a doctor diagnose anaemia due to iron deficiency?

First, the doctor must be sure that the patient suffers from anaemia and will probably request a blood test. With the result of the blood test, an analysis of the red blood cells will usually be included. In cases of pronounced iron deficiency the red blood cells will be small and pale.

An iron deficiency can be identified by techniques that examine the proteins involved in the storage and transport of iron through the body (ferritin and transferrin).

What can the doctor do to treat anaemia due to iron deficiency?

• Examine the patient and prescribe appropriate treatment to deal with the causes of the illness.
• Prescribe an iron supplement.

•  Iron preparations. Iron tablets will rapidly reverse anaemia if the underlying cause of blood loss has been treated. The tablets can irritate the stomach and should be taken after food if this is the case. Iron tablets may colour the stools black and may cause constipation or sometimes diarrhoea. Very occasionally there may be a need for intramuscular iron injections to be given instead of tablets, but this is far less common.

• Eating a varied diet.
• Good sources of iron include liver, beef, wholemeal bread, cereals, eggs and dried fruit.
• A doctor should always be consulted immediately if there is loss of blood in the stools or urine. Medical advice should also be sought about persistently heavy periods.
• A woman who is pregnant or planning to become pregnant, should talk to her doctor about iron supplements.