Home
Bupa members

Support and offers for individual members and customers

Anaemia - an overview

Published by Bupa's health information team, February 2008.

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

Anaemia is a condition where you have too few red blood cells or not enough haemoglobin in your blood. It can make you feel tired, breathless and faint.

About anaemia

Just over half the volume of your blood is made up of a yellowish watery fluid called plasma, which contains proteins, salts and other substances.

The rest of your blood is made up of the following cells and cell fragments, which are all produced in the bone marrow.

  • Red blood cells make up more than 99 percent of the cells in the blood and carry oxygen around the body in a substance called haemoglobin, which gives blood its red colour. Iron is an important ingredient of haemoglobin.
  • White blood cells are larger than red blood cells and make up less than one percent of the blood cells. There are several different types and they are important in protecting the body against infection.
  • Platelets are tiny fragments of cells that are involved in blood clotting.

Anaemia occurs when you don't have enough red blood cells, or enough of the oxygen-carrying pigment called haemoglobin. There are different types of anaemia, including pernicious anaemia, haemolytic anaemia, aplastic anaemia and sickle cell anaemia.

Symptoms of anaemia

The symptoms of anaemia include:

  • breathlessness with little exercise
  • feeling very tired
  • looking pale
  • being intolerant of cold temperatures
  • a rapid pulse
  • palpitations
  • headaches

Less common anaemia symptoms can include tinnitus (ringing in the ears) and an altered sense of taste. There may also be other symptoms of anaemia, which result from the underlying condition that is the cause of anaemia.

Causes of anaemia

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

Loss of blood

Blood loss can result from an obvious injury, or surgery, but it's not always easy to detect, especially if it's happening inside the body (eg a bleeding stomach ulcer). Women who have heavy periods can develop anaemia.

Not making enough red blood cells and/or haemoglobin

The bone marrow may not be able to make enough good-quality red blood cells because of a lack of essential vitamins such as vitamin B12 or folic acid, or because of a serious bone marrow disorder such as leukaemia or aplastic anaemia. Long-term (chronic) inflammation, for example in rheumatoid arthritis or long-term infections, may also suppress your bone marrow.

The most common cause is lack of haemoglobin due to iron deficiency. This usually results from long-term bleeding, for example in women, the monthly period (menstruation). The kidneys also have an important role because they produce a hormone called EPO, which tells the bone marrow to make red cells. If you have long-term kidney problems you may have anaemia due to the lack of EPO.

Red blood cells broken down too quickly

Red blood cells normally live for about 120 days before they are broken down and replaced. Various inherited problems with the red blood cells, or their haemoglobin, or an attack on normal red cells by the immune system, may cause them to be broken down too soon. This is called haemolytic anaemia. Some medicines may also be involved in causing haemolytic anaemia.

People with a condition called sickle-cell anaemia tend to have red blood cells that are broken down too soon. Sickle-cell anaemia is an inherited condition in which the red blood cells can become crescent-shaped rather than round due to the presence of an abnormal type of haemoglobin (haemoglobin S) These cells don't survive as well as normal red blood cells.

Diagnosis of anaemia

If you have symptoms of anaemia, such as breathlessness and fatigue, you should visit your GP. He or she will ask about your symptoms, any previous illnesses or treatments and your eating habits. You will probably have a physical examination.

If your doctor thinks you have anaemia, he or she will probably ask you to have a blood test. This involves taking samples of blood from one of the veins in your arm. The needle used is narrow and the amount of blood taken is small. For most people having a blood test is virtually painless.

The tests on your blood will include a full blood count (FBC), which is done by a machine in a hospital laboratory on a sample of your blood.

A full blood count gives information about your haemoglobin levels and how many of each of the different types of blood cells you have, as well as information about the size of your red cells (MCV) and the amount of haemoglobin each one contains (MCH). In America, the same test is known as a complete blood count (CBC).

The normal amount - or concentration - of haemoglobin for men is at least 13g/dl (13 grams of haemoglobin per decilitre of blood - a decilitre is 100ml) and 11.5g/dl for women. If your haemoglobin level is lower than this you have anaemia.

If your haemoglobin level is low, the other results from a full blood count can give clues about what might be causing anaemia. For example, if your haemoglobin is low and your red blood cells are small, you may have iron deficiency. However, if the haemoglobin is low and the red cells are large, you are more likely to have a deficiency of vitamin B12 or folate.

If the cause of anaemia isn't clear, your GP may recommend further tests. These might include investigations into possible blood loss from the stomach or bowel, so you may need to have a test to see if you have blood in your faeces. This is called a faecal occult blood test. If your doctor suspects that you are losing blood into your gastro-intestinal tract you may also be offered an endoscopy. This is an examination of the lining of the stomach (gastroscopy) or large bowel (colonoscopy) using a thin, flexible telescope.

Your GP may also refer you to a haematologist - a doctor specialising in conditions of the blood - for further tests, which may include taking a sample of your bone marrow.

Treatment of anaemia

Treatment of anaemia depends on its underlying cause. You may need to improve your diet or your doctor may recommend that you take supplements of iron, folic acid or vitamin B12. If you are severely anaemic due to a serious underlying condition, you may need a blood transfusion. Or, if you have a condition such as chronic kidney disease, you may need to have injections of the hormone EPO.

Prevention of anaemia

The best way to prevent anaemia is to eat a healthy, balanced diet. For most people, this sort of diet provides enough essential nutrients, without the need for supplements.

As a guide, the main nutrients you need to make healthy red blood cells are:

  • iron - in meat, liver, green vegetables, dried fruit, pulses (eg chick peas and lentils) and fortified foods such as some breakfast cereals and bread
  • vitamin B12 - in meat, milk, cheese, eggs and fortified foods such as some breakfast cereals and bread. It is not found in vegetables
  • folate - in liver, yeast extract, green leafy vegetables (such as peas and spinach), oranges, milk and fortified foods such as some breakfast cereals and bread

If you don't eat animal products (a vegan diet) or have a condition that affects how well you can absorb nutrients (eg coeliac disease), you may need to take supplements of nutrients. You should also get advice from a doctor or a registered dietician.

If you are pregnant, you are more likely to get a form of iron-deficiency anaemia. Your antenatal checks will include regular blood tests to check your haemoglobin levels. Your doctor or midwife will prescribe iron supplements if you need them.

Further information

Related topics

Sources

  • Iron deficiency anaemia. Clinical Knowledge Summaries. http://cks.library.nhs.uk, accessed 2 January 2007
  • Simon C, Everitt H, Kendrick T. Oxford Handbook of General Practice. 2nd ed. Oxford: Oxford University Press, 2006: 422-423
  • Hoffbrand, A V, Moss, P A H, Pettit, J E. Essential haematology. 5th ed. Blackwell Publishing. 2006
  • Merck Manual Professional. Etiology of anemia. www.merck.com, accessed 2 January 2007

This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Bupa doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional.

Publication date: February 2008.

 

Rate this page

Feedback

Have you found the information in this factsheet helpful? Do take a couple of moments to give us your feedback.

Click here to give us your feedback

Up to £100 off a Bupa Health assessment

Bupa health insurance

Free online health check

Bupa Care Homes

Bupa travel cover