Anaemia

Anaemia is a condition in which the blood cannot carry enough oxygen, either because there is a low number of red blood cells or because each red blood cell is able to carry less oxygen than normal. There are many different types of anaemia with different causes.

Symptoms include feeling tired or faint and getting breathless easily. Treatment depends on what is causing the anaemia.

About blood

Blood is made up of fluid called plasma which contains three types of cells:

white blood cells - these are part of the immune system, the body's defence against infection
platelets - these are involved in blood clotting
red blood cells - these carry oxygen around the body in a pigment called haemoglobin. The main component of haemoglobin is iron

Red blood cells are made by the body in the bone marrow, and live for around four months before they are destroyed and replaced, as part of a normal renewal process.

What causes anaemia?

Anaemia is a condition in which the blood cannot carry enough oxygen to meet the needs of the body. This may be because there are less red blood cells than normal, or because there is not enough haemoglobin, the oxygen-carrying component of red blood cells, in each cell.

There are many possible causes of anaemia. The body may not be producing enough red blood cells to replace those that are destroyed. This can occur when the body lacks some of the substances that it needs to manufacture them, such as iron.

Iron deficiency is the most common cause of anaemia. Most people's diet contains enough iron, but at times the body may need more because it needs a larger supply of blood than usual. For example, during a growth spurt in childhood or during pregnancy.

Other vitamins that are needed to manufacture red blood cells include folate (folic acid) and vitamin B12. A lack of these in the diet can cause anaemia.

Losing too many red blood cells can also be a cause of anaemia. This results from bleeding, for example excessive menstrual bleeding, bleeding from the gut (which may go unnoticed and pass out in stools), or major surgery.

Anaemia can also be caused by red blood cell problems:

thalassaemia - a genetic disorder in which haemoglobin is not correctly formed
sickle cell anaemia - a genetic disorder in which the red blood cells are crescent-shaped rather than round and cannot carry oxygen as well as normal red blood cells
haemolytic anaemia - in which red blood cells are fragile and can get broken easily in the bloodstream

Red blood cell production can also be suppressed by treatments for cancer including chemotherapy and radiotherapy.

Problems with bone marrow and leukaemia can cause anaemia. Other medical conditions that can result in anaemia include kidney failure and rheumatoid arthritis.

The symptoms of anaemia

Common symptoms of anaemia, due to the reduced amount of oxygen in the body include:

breathlessness
tiredness
dizziness
rapid, weak pulse or palpitations
headaches

People with anaemia may also look pale.

Less common symptoms can include tinnitus (ringing in the ears) and altered taste.

Various other symptoms may result from the condition causing the anaemia.

Diagnosis

Anyone with symptoms that may be due to anaemia, such as paleness, weakness and fatigue, should visit their GP. He or she will ask about your symptoms, medical history and current eating habits, and may perform a physical examination.

A simple blood test can measure the number of red cells and the amount of haemoglobin in the blood. The normal amount is at least 13g/dl (13 grams of haemoglobin per decilitre of blood) for men and 11g/dl for women. This test can determine if you are anaemic, but does not identify the cause of the anaemia.

Sometimes the cause is clear, for example in women who are pregnant or who have heavy periods. However, if the cause is not clear, your GP may recommend further tests.

These may include investigations into possible bleeding in the gut, such as a colonoscopy. A colonoscopy is an examination of the lining of the colon (large bowel) using a flexible, tube-like telescope called a colonoscope. This instrument is carefully passed through your back passage and into the colon.

Treatment

Treatment for anaemia depends on its cause. For many people, treatment involves taking iron tablets or supplements of folic acid or vitamin B12. For some people, treatment is aimed at dealing with the underlying cause and so is more complex.

Prevention

The best way to prevent anaemia is to eat a healthy, balanced diet. The main sources of the nutrients you need to make healthy red blood cells are:

Iron - meat, liver, cereals, raw green vegetables, fortified foods such as some breakfast cereals.
Vitamin B12 - meat, shellfish, milk, cheese, and eggs. It is not found in any vegetable.
Folate - raw green vegetables, oranges, wholegrain cereals, some fortified foods such as breakfast cereals and bread.

Further information

Search for "anaemia" on healthinsite.gov.au

The information on this factsheet is intended to be a guide only and is not intended to be nor should be relied on as a substitute for professional medical advice. It is also not intended to be for medical diagnosis or treatment. BUPA Australia makes no warranties or representations regarding the quality, accuracy or completeness of the information. BUPA Australia is not liable to readers of the information for any loss or damage suffered arising out of the use of or reliance on the information, except that which can be excluded by law.