Blood test
Ferritin Test (Iron Stores)
A ferritin test measures the protein that stores iron in the body, giving a good indication of your iron levels. It helps diagnose iron-deficiency anaemia and iron overload.
Quick answer
Ferritin Test (Iron Stores): what it is and what the results mean
Ferritin is the main protein that stores iron in the body, so a ferritin blood test is a useful way to estimate whether iron stores are low, normal or high. It is often part of a wider set of "iron studies".
- Why it is done: It is used to investigate tiredness and anaemia, to confirm iron deficiency, to monitor treatment with iron, and sometimes to check for iron overload conditions such as haemochromatosis.
- Understanding results: A low ferritin strongly suggests low iron stores and is a common cause of anaemia, while a high ferritin can reflect iron overload but also rises with inflammation, so it is interpreted with other tests such as CRP and a full blood count.
What it is
Ferritin is the main protein that stores iron in the body, so a ferritin blood test is a useful way to estimate whether iron stores are low, normal or high. It is often part of a wider set of "iron studies".
Why it is done
It is used to investigate tiredness and anaemia, to confirm iron deficiency, to monitor treatment with iron, and sometimes to check for iron overload conditions such as haemochromatosis.
What to expect
A standard blood sample is taken from the arm; fasting is not usually required.
Understanding the results
A low ferritin strongly suggests low iron stores and is a common cause of anaemia, while a high ferritin can reflect iron overload but also rises with inflammation, so it is interpreted with other tests such as CRP and a full blood count.
Good to know
Risks and limitations
The test carries the minor risks of any blood test. Because ferritin rises with inflammation, a "normal" or high level does not always rule out iron deficiency, so results are read in context.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Ferritin Test (Iron Stores): frequently asked questions
What does low ferritin mean?
Low ferritin usually means low iron stores, which is a common cause of iron-deficiency anaemia and tiredness. Your clinician will look for the cause and may advise iron treatment.
Can ferritin be high without iron overload?
Yes. Ferritin rises with inflammation or infection, so a high level does not always mean too much iron. It is interpreted alongside inflammatory markers and other iron tests.
Related tests
Other blood test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Royal College of Pathologists / relevant professional body
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