Summary

Iron Studies is the name of a group or panel of blood tests that collectively looks at how much iron is in your blood and body. Your doctor may request iron studies if you have symptoms of having too little or too much iron. 

The iron studies panel is made up of several tests, most commonly:
- Ferritin
-Serum iron
-Transferrin
-Transferrin saturation or
-Total iron binding capacity (TIBC)

The tests included in the iron studies panel may vary slightly depending on the lab doing the testing. Each test measures a different aspect of the storage and transportation of iron in the blood. By assessing each result, your doctor can build up a picture of your overall iron status. 

Why get tested?

Iron is an essential mineral that is needed by the body to form haemoglobin.  Haemoglobin is the protein in red blood cells that binds oxygen in the lungs and releases it as blood travels to other parts of the body.

If your iron levels are too low your body will not be able to make enough haemoglobin needed to function normally. This condition is known as iron-deficiency anaemia. It is also possible to have too much iron. This is known as iron overload and it may be caused by an inherited condition called haemochromatosis.

What tests are included in the iron studies panel?

The tests used to assess your iron status are those that are affected by the levels of iron in your body and they include:

Ferritin - iron storage

Iron is stored inside cells in a protein called ferritin.      

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.                

Your blood ferritin levels reflect the total amount of iron stored in the body. 

In iron deficiency anaemia, ferritin levels are usually low.

Measuring ferritin is less useful if you have inflammation such as during an infection or after an operation.  In these cases, ferritin may be misleadingly normal despite the presence of iron deficiency.

Transferrin and total iron binding capacity (TIBC) - iron transportation

When iron is released into the blood it binds to a protein called transferrin and is transported to where it is needed.

Your body makes transferrin in relation to your need for iron.  When iron stores are low, transferrin levels increase. When there is too much iron in the body transferrin levels are low. 

Transferrin and TIBC (total iron binding capacity) are different tests that measure the same thing — the amount of iron that can be transported in your blood. TIBC is an older test that is no longer routinely measured by most labs.

Serum iron concentration

The amount of iron that circulates in the blood varies markedly throughout the day

Measurement of iron alone is rarely helpful and needs to be combined with the results of other iron study tests to provide accurate results. It is most useful in calculating transferrin saturation.

Transferrin saturation

The serum iron result and the transferrin result can be combined to calculate the transferrin saturation (TFSAT).

The TFSAT tells us what percentage of all the transferrin in the blood contains iron.

The TFSAT level is usually between 15 and 45 per cent.

In iron deficiency, the TFSAT level will be low, and if there is too much iron in the body the TFSAT will be high.

Iron related health disorders

Too little iron (iron deficiency)

Normal iron levels are maintained by a balance between the amount of iron taken into the body and the amount of iron lost. Normally, we lose a small amount of iron each day, so if we consume insufficient iron to replace the lost iron, deficiency can develop over time.  

Causes of iron deficiency include:

• Inadequate iron in the diet (e.g. vegetarians and vegans) 
• Pregnancy (there is an increased iron requirement due to the growing fetus)
• Malabsorption of iron (for example in those who have had bowel or stomach surgery, or in those with inflammatory bowel disease).
• Chronic bleeding (for example, iron loss from a bleeding stomach ulcer)

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 that occurs is that iron stores are used up. In this stage, ferritin will be low, but iron and transferrin may be normal and there is no anaemia. As iron deficiency worsens, blood iron levels fall, TIBC and transferrin rise, and red blood cells may start to become small and pale, but there is still an adequate number of red blood cells. With prolonged or severe iron deficiency, anaemia develops.

Common symptoms of iron deficiency include tiredness, weakness, headache, and restless leg syndrome.

With longstanding iron deficiency, iron stores are used up and there is insufficient iron to make enough haemoglobin — a condition known as iron deficiency anaemia.  The red blood cells will be smaller than usual (microcytic) and paler than normal (hypochromic).

Too much iron (iron overload, haemochromatosis)

In iron overload, caused by haemochromatosis, excess iron builds up in the organs and may result in liver disease, diabetes, arthritis and pituitary gland disorders.  See the Test called HFE Mutations for more information.

Another cause of iron excess is regular blood transfusions.  The iron from the transfused red blood cells can accumulate in the body and cause similar symptoms to haemochromatosis.

Testing for iron status

If a problem with iron is suspected, your doctor may first request a full blood count (FBC), which provides information on the number, size and shape of the red blood cells and how much haemoglobin is in the blood.  If the full blood count suggests iron deficiency, your doctor will request iron studies as the next investigation or a full blood count and iron studies may be requested at the same time. 

Having the test

Blood

Any preparation?

None.

Your results

Summary of the changes in iron test results seen in various disorders 
 

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 themeverything 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. 

Questions you may consider asking include the following:

• 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?

Any more to know?

There are many different conditions that can cause anaemia other than iron deficiency. If your iron studies results do not suggest a problem with your body's iron levels you may need further tests to investigate other possible causes of your symptoms.
If your iron studies results suggest that you have iron deficiency, you may need to take iron supplement tablets, or your doctor may arrange for you to have an intravenous iron infusion.  In rare cases of severe iron deficiency, you may need a blood transfusion.  If the cause of the iron deficiency is not known you will need more tests to identify the underlying cause. For example, you may need to have an endoscopy or colonoscopy to look for any intestinal bleeding.

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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