Anaemia - an overview

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

This factsheet is for people who have anaemia, or who would like information about it.

Anaemia is a condition in which your blood can't carry enough oxygen to meet the needs of your body. This is because there are either insufficient red blood cells or not enough haemoglobin in the red cells.

About anaemia

Anaemia is a disorder of the blood. If you have anaemia, it means you have a reduced level of the protein in your blood that carries oxygen, called haemoglobin.

Your blood is made up of fluid called plasma and blood cells, which include the following.

• Red blood cells (erythrocytes) that contain haemoglobin.
• White blood cells (leucocytes) that are part of your immune system and help fight infection.
• Platelets (thrombocytes) that are tiny fragments of cells that help your blood clot.

Blood cells are made by your bone marrow, which is a spongy substance in the centre of your bones.

There are many types of anaemia, which are categorised according to their cause, including iron deficiency, vitamin B12-deficiency, folate-deficiency and sickle cell disease. For more information on specific types of anaemia, please see Related topics.

Symptoms of anaemia

Common symptoms of anaemia include: 

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

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

Complications of 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. There are other, different complications related to specific types of anaemia.

Causes of anaemia

There are many possible causes of anaemia. Most fall into the following three groups. 

• Bleeding. You can lose a lot of blood through an injury, an operation, from a stomach ulcer, or if you have prolonged or heavy periods.
• Reduced production of red blood cells and/or haemoglobin. Your body may not make enough healthy red blood cells and/or haemoglobin. This can happen if you don’t have enough iron, vitamin B12 or folate in your diet, or have health problems that stop the absorption of nutrients (for example Coeliac disease). Alternatively, the production of red blood cells may be defective (for example bone marrow disease or kidney disease).
• Rapid destruction of red blood cells. Red blood cells usually survive for about 120 days before they are broken down and replaced. Certain medicines can cause this to happen, as can a number of inherited conditions such as sickle cell anaemia.
• Premature destruction of red blood cells. Sometimes, your body can produce antibodies that destroy red cells before their full lifespan is complete. This is known as haemolytic anaemia.

Diagnosis of 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 to be 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. Your blood will be looked at under a microscope to check the size and shape of your red blood cells and to assess the different white cells that are present.
• Vitamin B12, iron and folate. The levels of each of these will be measured.

If you’re deficient in iron, your GP may also ask for a sample of faeces (also called a stool sample), which will be sent to a laboratory to determine if you have any bleeding from your stomach or bowel. This is called a faecal occult blood (FOB) test.

You may need to have further tests to help identify the cause of your anaemia. Depending on the type of anaemia you have, your GP may refer you to a haematologist (a doctor who specialises in identifying and treating conditions of the blood) for treatment.

Treatment of anaemia

The treatment you have will depend on the cause of your anaemia and can vary considerably from person to person. For example, some people may need to adjust their diet and take supplements of iron, folic acid or vitamin B12, whereas others may need to have a blood transfusion. People who have anaemia that is caused by kidney failure will need to have injections of the hormone erythropoietin (also known as Epo).

Prevention of anaemia

You can reduce your risk of developing anaemia by eating a healthy, balanced diet. For most people this will provide enough essential nutrients without the need to take supplements.

The best sources of iron and vitamin B12 are red meat and fortified foods (those that have particular nutrients added during their manufacture), such as breakfast cereals and bread. Green vegetables, dried fruit, chickpeas and lentils are also good sources of iron, as are milk and cheese. Eggs are also a good source of vitamin B12.

The best sources of folate are green vegetables, such as broccoli, Brussels sprouts, asparagus and peas. Chickpeas and brown rice are also good sources.

If you have a condition that affects how well you absorb nutrients, or if you’re pregnant, you may need to take supplements. Women who are menstruating may benefit from taking iron tablets. Ask your GP for advice.
 

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

For sources and links to further information, see Resources.