There are several causes of anaemia. They include:

	Defective bone marrow
	A shortage of iron, the main ingredient of haemoglobin
	A shortage of the vitamins B12 or folic acid, both needed to produce red blood cells
	Loss of blood, through heavy menstruation, or internal bleeding, which may be caused by disease
	Infections such as malaria

What is the most common form of anaemia?

By far the most common form of the condition is caused by iron deficiency.

Lack of iron prevents the bone marrow from making sufficient haemoglobin for the red cells.

The cells produced are small and pale and have a reduced oxygen-carrying capacity.

The problem can be down to a lack of iron in the diet. Good sources of iron include fruit, wholemeal bread, beans, and lean meat.

It may also be that the gut is unable to effectively absorb iron from the diet. This may be due to coeliac disease, a disorder that impairs digestion.

However, the main cause of iron-deficiency anaemia is loss of iron at a greater rate than normal as a result of abnormally heavy or persistent bleeding.

In some cases this may be caused by disease.

The diseases most commonly responsible for persistent bleeding are those associated with the digestive tract, such as gastritis, peptic ulcer, stomach cancer, inflammatory bowel disease, haemorrhoids, and bowel tumours.

Prolonged treatment with aspirin and similar nonsteroidal anti-inflammatory drugs can also cause gastrointestinal bleeding.

What are the symptoms?

The first symptoms of anaemia are tiredness and palpitations.

Other common symptoms include shortness of breath and dizziness.

If the anaemia is severe there is a risk of angina (chest pain), headache and leg pains.

The body's ability to fight infection is also compromised.

Long-term anaemia caused by iron deficiency can cause a range of symptoms including:

	A burning sensation in the tongue
	Dryness in the mouth and throat
	Sores at the corners of the mouth
	An altered sense of touch
	Difficulty in swallowing
	Brittle hair

While younger people can be severely anaemic but not really have any symptoms, older people have less reserves in their muscles and brains and other organs, so they will feel the effects much more.

How is anaemia treated?

The most common way to treat anaemia caused by iron deficiency is to prescribe an iron supplement. 

Some hospital patients may even be given injections, and if iron depletion is very severe blood transfusions may be necessary.