Summary

• Ferritin is a blood protein that stores iron, mainly in the liver, releasing it when it is needed.
• When your body uses iron, cells release a small amount of ferritin into your bloodstream. Because of this, your ferritin level reflects the amount of iron stored in your body.
• Having either too little or too much iron can cause serious health problems.
• A ferritin test can be used by itself, but it is most often ordered as part of a group of tests known as iron studies which includes other tests relating to your body's iron levels.

How iron is used

Your body needs iron for daily activities, growth and development. It uses iron to make haemoglobin, the protein in red blood cells that gives them their colour, and which carries oxygen through the bloodstream. It also helps provide oxygen to muscles and helps make some hormones. 

Our bodies cannot make iron. It must be absorbed from our diet or from supplements. The amount of iron we absorb is decided by our body's needs. We normally use just a little bit of iron each day and we don’t have a way of getting rid of excess iron. Instead, the body closely controls iron levels by regulating how much iron we take in from our diet.

How iron is taken up and used

• Iron is absorbed from your diet into the bloodstream through your small intestine. Once the iron enters the blood, it sticks to a protein called transferrin. Transferrin transports it to various tissues throughout the body.
• Iron is stored in a protein called ferritin. This is found all over your body but mainly in your liver. Ferritin releases iron as it is needed when your body detects low iron levels in your blood.
• Entering the bloodstream, iron once again sticks to transferrin, and it travels to the bone marrow where new blood cells are made.
• Here it is taken up by newly forming red blood cells which have transferrin receptors on their surface. Entering through the receptors, transferrin with iron attached moves into the cell where the iron is separated from the transferrin.
• Since red blood cells live for an average of about 120 days, the body needs a constant supply of iron to maintain haemoglobin levels. Dying red blood cells are recycled and old haemoglobin is broken down to rebuild iron supplies.

Why get tested?

When the body needs to make new red blood cells the iron stored in ferritin is released into the blood stream and transported to the bone marrow where blood cells are made. Measuring the level of ferritin in your blood is a good indication of the amount of iron stored in your body.

If your iron stores are too low (iron deficiency) you may not be able to make healthy new red blood cells and this can lead to anaemia.

It is also possible to have too much iron in the body, a condition called iron overload, which can also cause health problems. For more information about how the body uses iron see Iron Studies.

A ferritin test can be used by itself, but it is most often ordered as part of a group of tests known as iron studies which includes other tests relating to your body's iron levels.

Having the test

Sample
Blood.

Any preparation?
None.

Your results

Low ferritin levels are usually due to iron deficiency. Iron deficiency anaemia comes on gradually. When the rate of iron loss is more than the amount of iron you absorb from your diet the first thing to happen is that iron stores are used up.

A high ferritin level may be due to having too much iron. However, ferritin levels also increase when there is inflammation in the body such as during an infection, after surgery, or if you have an autoimmune disorder or liver disease. This means a high ferritin result can be difficult to interpret on its own. There are many causes of iron deficiency, and you may need further tests to work out the cause. Your medical team will use the results of these other blood tests and your symptoms to better understand the ferritin result.

Because ferritin goes up during inflammation it is also possible to have iron deficiency despite the ferritin being normal or even high. This will be considered when interpreting your results.

Reference intervals - comparing your results to the healthy population

Your results will be compared to reference intervals (sometimes called a normal range).

• Reference intervals are the range of results expected in healthy people.
• They are used to provide a benchmark for interpreting a patient's test results.
• When compared against them, your results may be flagged high or low if they sit outside this range.
• Some reference intervals are harmonised or standardised, which means all labs in Australia use them.
• Others are not because for these tests, labs are using different instruments and chemical processes to analyse samples.
• Always compare your lab results to the reference interval provided on the same report.

If your results are flagged as high or low this does not necessarily mean that anything is wrong. It depends on your personal situation.

Ferritin reference intervals

There is no standardised reference interval for ferritin, however a universal reference range with a low end of 30 mg/L for ferritin in all adults has been adopted by some pathology providers to improve the diagnosis of iron deficiency, especially in women. In cases of suspected or known inflammation, a higher cutoff of 70 mg/L is often used.

The upper limit is typically set at about 200 µg/L for women and 300 µg/L for men. These remain sex-specific because iron overload risk differs between men and women.

It is important to talk with your doctors when reading your results report.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How will the results from this test change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record. You and your healthcare provider can now access your results whenever and wherever needed.

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