Glossary term
Ferritin
Part of: Blood Test Results
- Reading time
- 4 min read
- Last reviewed
- Last reviewed January 1970
- Reading level
- Written in plain English
- Reviewed by
- Reviewed by Medipher Editorial Team
A protein that stores iron in your body. Ferritin levels are used to estimate your total iron stores.
Medipher explains medical wording in plain English — it does not diagnose or replace a clinician. If this is a medical emergency, call your local emergency number immediately.
Simple visual explanation
What is this?
Ferritin is the protein your body uses to store iron safely until it's needed — mostly in the liver, spleen and bone marrow.
Because ferritin holds most of your iron reserves, the ferritin level in your blood is a good indirect measurement of how much iron you have stored.
Ferritin is also an 'acute-phase' protein, meaning it can rise temporarily during infection, inflammation or illness — which is why it's usually interpreted alongside a full picture.
The test itself is a simple blood sample and doesn't require fasting.
Why is it important?
Ferritin is one of the earliest and most sensitive markers of iron deficiency, often falling before haemoglobin does.
It helps clinicians tell iron-deficiency anaemia apart from other causes of anaemia, which changes what treatment is offered.
Ferritin also guides whether to look for a source of blood loss and when to consider iron supplements or infusion.
Where you'll see it: Blood test reports, usually alongside a full blood count when iron deficiency is suspected.
How doctors use this result
Clinicians may use this result to:
- Investigate tiredness, breathlessness or hair loss.
- Confirm iron deficiency as the cause of anaemia.
- Guide whether to look for hidden blood loss in the gut.
- Monitor the response to iron supplements or infusion.
What's the normal range?
| Adult women (typical) | 15–150 µg/L |
| Adult men (typical) | 30–400 µg/L |
Ranges vary between laboratories. Values below ~30 µg/L often suggest low iron stores even without anaemia.
Interpretation depends on age, sex, pregnancy, symptoms and whether inflammation is present — so a value in-range can still mean low iron if there's recent illness masking it.
Normal ranges are guides, not verdicts. Interpretation depends on your age, sex, symptoms, medical history, medications and other investigations — which is why your clinician looks at the whole picture rather than a single value.
Common reasons it may be high
Infection or inflammation
Ferritin rises temporarily as part of the body's response and usually settles when the illness clears.
Liver conditions
Damaged liver cells release stored ferritin into the blood.
Excess alcohol use
Alcohol affects both the liver and iron storage, raising ferritin over time.
Iron overload (uncommon)
An inherited condition called haemochromatosis stores excess iron; specialist review is needed.
Common reasons it may be low
Diet low in iron
Iron intake below what the body uses gradually depletes stores.
Heavy or long menstrual periods
Regular blood loss uses iron faster than diet replaces it.
Pregnancy and breastfeeding
Iron demand is higher for the growing baby and milk production.
Coeliac or other gut conditions
Reduce iron absorption even when the diet is adequate.
Hidden blood loss in the gut
Slow, unseen bleeding — for example from ulcers — can gradually drain iron stores.
Does an abnormal result always mean something is wrong?
Not necessarily. A number that sits outside the printed range is a prompt for interpretation — not a diagnosis.
- A single result rarely gives the full picture — clinicians interpret it alongside your symptoms.
- Your medical history, medications and other blood tests all shape the meaning of one value.
- Small movements just outside the reference range are common and often not concerning.
- Repeat testing over time is frequently more useful than any single number.
What might happen next?
- A discussion about diet, periods and gut symptoms.
- Iron supplements or dietary changes if levels are low.
- Further tests to look for a cause of blood loss when appropriate.
- Repeat ferritin after treatment to confirm improvement.
One result rarely tells the whole story. Clinicians look at your symptoms, medical history, medications and other tests together — and a single value that sits slightly outside the reference range is often normal for you. Repeat testing over time is frequently more useful than any one number. Medipher helps you understand what a result means in plain English, but it cannot diagnose medical conditions or replace advice from a doctor, nurse or pharmacist.
When should I speak to a healthcare professional?
Speak with your GP or another healthcare professional if:
- You've been asked to repeat the test.
- You're experiencing new or worsening symptoms.
- Your clinician has flagged the result as needing follow-up.
- You don't understand your results or feel unsure what to do next.
If you have severe symptoms — chest pain, severe breathlessness, fainting, heavy bleeding or feel very unwell — seek urgent help. If this is a medical emergency, call your local emergency number immediately. Medipher is designed to help explain medical information and is not an emergency service.
Frequently asked questions
Related blood tests
Terms clinicians often look at alongside Ferritin.
Related guides
Still unsure what your result means?
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Sources
General patient information referenced when writing this page.
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A short summary and recommended next reads are just below.
Continue learning
- Next upAnaemiaA condition where you don't have enough healthy red blood cells or haemoglobin to carry oxygen around your body.
- Next upAlbuminThe main protein in your blood, made by the liver. It helps keep fluid inside your blood vessels.
- Next upALTAn enzyme found mainly in liver cells. It leaks into the blood when the liver is irritated or damaged.
This glossary entry is general health information, not medical advice. Medipher explains medical wording in plain English and does not diagnose, provide treatment advice, or replace a GP, doctor, nurse or pharmacist. Always discuss your results with a qualified clinician.