There are four main types of anaemia, which is a disorder of the blood in which haemoglobin (the oxygen-carrying pigment in red blood cells) is deficient or abnormal.

As the oxygen-carrying power of the blood is reduced, the tissues of the body may not receive sufficient oxygen giving rise to the classical symptoms of anaemia – paleness, tiredness and shortness of breath.

What Are The Types?

There are four forms of anaemia.

  1. By far the most common type is deficiency anaemia, one of which results from low levels of iron in the body – iron-deficiency anaemia. Low levels of other substances, such as vitamin B12 and folic acid, can lead to another deficiency anaemia – megaloblastic anaemia.
  2. Inherited abnormalities of haemoglobin production, such as sickle-cell anaemia and thalassaemia. The haemoglobin is abnormal from shortly after birth, but symptoms of anaemia may not develop until later in childhood.
  3. Excessively rapid destruction of red blood cells (haemolysis) is called haemolytic anaemia.
  4. Failure of the bone marrow to produce enough normal red blood cells and often all the other types of blood cells as well. One form, aplastic anaemia, can be congenital or rarely, can be brought on by exposure to poisons, such as benzene, and certain drugs.

What Are The Symptoms of Anaemias?

All anaemias have the same symptoms:
• fatigue and a feeling of faintness
• pale skin
• shortness of breath on mild exertion
palpitations.
If the anaemia is severe and long term, stress on the heart may result in chronic heart failure, with swollen ankles and increasing shortness of breath.

Measures for Anaemias

Tests are aimed at discovering two things.
1. Finding out what kind of anaemia you have.
2. Finding out why you have that particular anaemia, i.e. the cause.
Investigation starts with simple blood tests but sometimes more complicated tests, such as taking a specimen of bone marrow from the hip bone, may be needed.

What Is The Treatment of Anaemias?

Most anaemias respond well to treatment, although some severe cases may require blood transfusion to ensure immediate improvement. If there is an underlying condition, such as a chronic peptic ulcer, your doctor will treat it too.

Iron-Deficiency Anaemia

Iron-deficiency anaemia is the most common form of anaemia. Iron is an essential component of haemoglobin. 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 carry it to the body tissues. Consequently, the tissues receive insufficient oxygen.

What Are The Causes of Iron-Deficiency Anaemias?

■ Iron-deficiency anaemia is most commonly caused by the loss of significant amounts of iron through persistent bleeding. Iron-deficiency anaemia occurs mainly in women who experience regular blood loss over a period of time from heavy menstrual bleeding. Persistent loss of blood may also be due to peptic ulcers. The prolonged use of aspirin or long-term use of non-steroidal anti-inflammatory drugs (NSAIDS) are possible causes of bleeding from the stomach lining. In people over the age of 60, a common cause of blood loss is cancer of the bowel. Bleeding in the stomach or upper intestine may go unnoticed, while blood lost from the lower part of the intestine or 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 this 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, women who are pregnant and children who are growing rapidly, especially adolescents, 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. Iron is absorbed from food while it passes through the small intestine and conditions that damage it, such as coeliac disease, may result in iron deficiency.

What Are The Symptoms of Iron-Deficiency Anaemias?

You may experience the symptoms of an underlying disorder, along with the general symptoms of anaemia, such as:

• fatigue and a feeling of faintness
• pale skin
• shortness of breath on mild exertion
palpitations.

You may also have symptoms that are specifically due to a marked deficiency of iron. These include:

• brittle, concave-shaped nails
• painful cracks in the skin at the side 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.

What Might Be Done of Iron-Deficiency Anaemias?

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 laboratory tests may also be necessary. For example, a sample of faeces may be tested for signs of intestinal bleeding.
Your doctor will treat any underlying disorder such as a stomach ulcer. Iron tablets (syrup lor children) or, less commonly, iron injections for several months will replace iron stores. Severe cases of anaemia may require blood transfusion.

Megaloblastic Anaemia

Megaloblastic anaemia is a type of anaemia caused by lack of vitamin B12 or folic acid. These two important vitamins play an essential role in the production of healthy red blood cells. Deficiency of either vitamin may lead to megaloblastic anaemia, in which large, abnormal red blood cells (megaloblasts) form in the bone marrow and the production of normal red blood cells is reduced.

What Are The Causes of Megaloblastic Anaemia?

In the West, lack of vitamin B12 is rarely due to a dietary deficiency. The problem is usually due to an autoimmune disorder, in which antibodies damage the stomach lining and prevent it from forming intrinsic factor, which is vital for absorption of vitamin B12 from food in the intestines. The resulting anaemia, called pernicious anaemia, tends to run in families and is more common in women and in people with other autoimmune disorders. Intestinal disorders, such as coeliac disease, or surgery on the stomach can also interfere with vitamin B12 absorption.

Folic acid deficiency is often due to a poor diet. People who abuse alcohol are at particular risk because alcohol interferes with the absorption of folic acid. Pregnant women may also be at risk because folic acid requirements are higher in pregnancy. Disorders causing a rapid turnover of cells, including severe psoriasis, may also cause folic acid deficiency. In rare cases, the deficiency is a side effect of certain drugs, such as anticonvulsants and anticancer drugs.

What Are The Symptoms of Megaloblastic Anaemia?

The initial symptoms of megaloblastic anaemia, which are common to all anaemias, develop slowly and may include:
• fatigue and a feeling of faintness
• pale skin
• shortness of breath on mild exertion
palpitations.

These symptoms of megaloblastic anaemia may worsen over time. Although lack of folic
acid does not produce additional symptoms, lack of vitamin B12 may eventually damage
the nervous system, possibly leading to:

• tingling of the hands and feet
• weakness and loss of balance
• loss of memory and confusion.

What Might Be Done for Megaloblastic Anaemia?

The diagnosis requires blood tests to look for megaloblasts and to measure the levels of
vitamin B12 and folic acid. You may also have a bone marrow aspiration and biopsy to obtain
tissue samples for further examination. Megaloblastic anaemia caused by an inability
to absorb vitamin B12 may be improved by treating the underlying disorder, but some
people, such as those with pernicious anaemia and malabsorption caused by surgery, need
lifelong monthly injections of vitamin B12.

Symptoms should begin to subside within days, but existing damage to the nervous system may be irreversible. If megaloblastic anaemia is caused by an inadequate diet, the condition usually disappears with an improved diet and a short course of folic acid tablets.

Sickle-Cell Anaemia

Sickle-cell anaemia is an inherited condition caused by an abnormal form of haemoglobin
in the blood. The inheritance is recessive; that is, both parents carry an abnormal gene but
are themselves healthy. The anaemia that results from the blood condition is not present
at birth but develops in the first six months. Sickle-cell anaemia is more common in people
of African descent.

What Are The Causes of Sickle-Cell Anaemia?

Haemoglobin is the protein contained in red cells in the blood. It picks up oxygen from
the blood and carries it to various parts of the body. Sickle-cell anaemia occurs when the
abnormal haemoglobin causes the red blood cells to become sickle-shaped as a result of low
oxygen levels. This may lead to a sickle-cell crisis, involving severe joint and abdominal
pain. Immediate medical attention is needed.

What Are The Symptoms of Sickle-Cell Anaemia?

People with sickle-cell anaemia may have the following symptoms:

• anaemia
• fatigue
• mild jaundice – the whites of the eyes may be slightly yellowed
• pain in the limbs and abdomen
• susceptibility to infection leading to frequent colds and illnesses.

What Might Be Done of Sickle-Cell Anaemia?

It is essential for people with sickle-cell anaemia to be fully immunized against all
infectious diseases and to take any prescribed vitamin supplements. Some people may need
to take penicillin regularly to prevent certain bacterial infections. A sickle-cell crisis may be
precipitated by strenuous exercise, particularly in the cold and damp, and this should be
avoided. If a sickle-cell crisis occurs, it will be treated with painkilling drugs.

As sickle-cell anaemia is inherited, it is important for potential carriers to seek genetic
counselling before deciding to have a baby. A blood test will show if the prospective parents are carriers of the disease.

Thalassaemia

Thalassaemia is a form of genetically inherited anaemia. It occurs mostly in people from the
Mediterranean area but it can also affect people from India and Southeast Asia. Thalassaemia can be passed on to a child if both parents carry the faulty gene. In thalassaemia, the body cannot make normal haemoglobin, the substance in the blood that makes the cells red and carries oxygen through the body. The problem reveals itself when a baby is about three months old with symptoms of severe anaemia.

What Are The Symptoms of Thalassaemia?

Thalassaemia causes the following symptoms:

• fatigue
• breathlessness
• pallor of the lips, tongue, hands and feet
• loss of appetite accompanied by a swollen abdomen.

What Might Be Done for Thalassaemia?

Treatment for thalassaemia requires regular blood transfusions, usually every 6-8 weeks, to prevent severe anaemia from developing. The spleen is also sometimes removed, reducing the need for frequent transfusions. If a person with thalassaemia has too many transfusions, iron can build up in the body and damage the liver, pancreas and heart. There is now a drug available that helps the body get rid of excess iron; the treatment is sometimes carried out overnight by means of a continuous injection, into the skin.

If you are from a group particularly susceptible to the disease, you and your partner may wish to seek genetic counselling before trying to conceive to find out if one or both of you might be a carrier of the gene responsible for thalassaemia.