- Red blood cells and haemoglobin, the molecule in red blood cells that makes them red, are important because they carry oxygen from the lungs around the body.
- Anaemia is when you don’t have enough red blood cells or haemoglobin.
- There are many different causes of anaemia.
- The most common type of anaemia is iron-deficiency anaemia, which is usually caused by not eating or absorbing enough iron, or by losing blood.
- It’s important to treat the cause of anaemia so it doesn’t recur.
What is anaemia?
Anaemia is when you don’t have enough red blood cells or haemoglobin. Red blood cells and haemoglobin, the molecule in red blood cells that makes them red, are important because they carry oxygen from the lungs around the body. It’s important to find and treat the cause of the anaemia to prevent it coming back, as well as the anaemia itself.
What are the symptoms of anaemia?
If you have anaemia, you may experience a range of symptoms, including:
- fatigue or weakness
- a fast heartbeat or heart palpitations
- dizziness, light-headedness or headaches
- shortness of breath, even when doing things you could usually do easily
You may also look pale and have cold feet or hands.
Depending on the underlying cause of your anaemia, you may have other symptoms too.
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What are the different types of anaemia?
There are a few different types of anaemia including:
- Iron-deficiency anaemia is the most common form of anaemia. It happens when you don’t eat or absorb enough iron in your diet, or if you experience blood loss.
- Pernicious and B12 deficiency anaemias are due to a lack of vitamin B12, which is needed to make healthy red blood cells. They can occur if you don’t eat enough foods containing vitamin B12, or if you have a medical problem that stops you absorbing vitamin B12 from foods. Pernicious anaemia is also known as ‘megaloblastic anaemia’, because it causes the red blood cells produced to be larger than normal.
- Anaplastic anaemia occurs when your bone marrow stops functioning normally and produces less red blood cells than your body needs.
- Haemolytic anaemia is when red blood cells die or are destroyed early in their lifecycle, so you don’t have enough of them in your body to do their job.
- Chronic diseases such as chronic kidney disease and heart failure can also cause anaemia.
Many different medical conditions can cause each of these types of anaemia, including:
- inherited conditions, such as thalassemia or sickle cell anaemia
- viral infections
- autoimmune conditions
- chronic diseases
What causes iron-deficiency anaemia?
Anaemia is most commonly caused by iron deficiency, which can develop for several reasons:
- If you are not eating enough foods that are rich in iron. Iron is important for the production of red blood cells. People who follow vegan and vegetarian diets need to be extra careful to include iron-rich foods in their diet.
- If you are unable to absorb iron from the food you eat. Some health conditions affect how much iron you can absorb from your stomach and bowel, such as coeliac disease.
- If you experience blood loss. Females are at increased risk of anaemia due to menstruation or heavy periods — 3 in 10 females of child-bearing age have anaemia. People with conditions such as Crohn’s disease, ulcerative colitis or stomach ulcers may also experience anaemia, due to bleeding in the stomach or bowel. Regular blood donors are at risk of developing anaemia too.
- If you have certain inherited or bone marrow diseases, including thalassaemia.
- Some females develop iron-deficiency anaemia during pregnancy due to their increasing need for iron throughout the pregnancy.
Other types of anaemia have other causes, which vary widely.
When should I see my doctor?
It’s important to see your doctor if you have any of the symptoms of anaemia or are worried about your iron levels.
Anaemia can cause a wide range of symptoms, depending on the underlying cause. Your doctor is the best person to assess you and refer you for the right investigations to identify the cause of your anaemia, so it can be treated effectively.
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How is anaemia diagnosed?
A blood test called a full blood count is used to look at the amount of haemoglobin in your blood. If this is lower than it should be for your age and sex, you may have anaemia.
Your doctor may also refer you for a blood test to check your iron levels, or other vitamin levels, to help identify the cause of the anaemia.
A blood film, where a pathologist looks at the size and shape of your red blood cells, can also help determine the underlying cause of your anaemia.
If you have anaemia, your doctor will talk to you and examine you to work out how severe the anaemia is, and what the cause could be. You might be asked to have more tests, depending on what your doctor has learnt from talking to you and examining you.
How is anaemia treated?
It is important to identify the cause of anaemia to be able to treat it effectively. This is usually done in 2 stages:
- Stage 1 involves treating the anaemia. This will depend on the cause of the anaemia, and may include, for example, taking iron or vitamin B12 supplements, or getting a blood transfusion.
- Stage 2 involves finding and treating the underlying cause of the anaemia. This will help prevent you getting anaemia again.
How is anaemia prevented?
Not all types of anaemia are preventable.
You can reduce your chances of getting some types of anaemia by:
- having a healthy diet that includes iron-rich foods
- taking a B12 supplement if you are a strict vegan
- seeing your doctor regularly if you have a chronic health condition or if you have symptoms of anaemia
You should only take iron supplements if they are recommended by your doctor, as they can have side effects.
Resources and support
Dieticians Australia offers advice on iron levels, sources of dietary iron and eating to increase iron absorption.
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Last reviewed: December 2022