Iron studies and full blood count
Iron stores and anaemia in one test. The first thing worth checking when you are exhausted, breathless or shedding hair.
Iron studies and a full blood count measure how much iron you have in storage, how much is moving around your blood, and whether a shortage has started to affect your red blood cells. The test is $69, and a KnowLuna doctor can request it for you at no extra charge. If you want your results explained in a 20-minute video consult, add a doctor consult for +$59. Collect at an accredited Australian centre, or choose a home kit or a nurse visit at checkout (options below).
What it measures
- Ferritin: the protein that stores iron, and the closest thing to a fuel gauge for your iron reserves. It is the marker that falls first and the one most worth knowing.
- Serum iron: the iron circulating in your blood right now. It swings through the day and with what you have eaten, so it is never read alone.
- Transferrin: the protein that carries iron around the body. It tends to rise when stores are low, as the body tries harder to collect what iron there is.
- Transferrin saturation: how much of that carrying capacity is actually filled, expressed as a percentage. Low saturation supports a picture of iron deficiency; a high one can point the other way.
- Full blood count: haemoglobin, red cell size and count, white cells and platelets. It shows whether low iron has tipped into anaemia, and gives a broad view of your blood.
Who it's for
Women with heavy or long periods, anyone who is exhausted, breathless on stairs, foggy, dizzy or noticing more hair in the brush, and women who are pregnant, recently postpartum or breastfeeding. It is also a sensible baseline before trying to conceive, and for vegetarians, vegans and endurance athletes. It is for adults aged 18 and over.
What you'll learn, and what you won't
You will learn whether your iron stores are full, borderline or empty, and whether your red blood cells have been affected. Ferritin and the full blood count are read together, because they describe two different stages of the same story.
What the test will not tell you is why. A blood test is one input to a doctor's assessment, not a diagnosis on its own. Low iron in a woman with heavy periods usually has an obvious explanation, but it can also come from what you absorb or from blood loss that needs investigating, and that is a conversation for a doctor rather than an assumption.
Why women run low
- Periods. Regular blood loss is the most common reason women run low, and heavy periods are often normalised for years before anyone checks.
- Pregnancy. Iron demand rises sharply, particularly in the second and third trimesters.
- Birth and breastfeeding. Blood loss at delivery plus the months that follow leave many women depleted, which is why iron is part of the postpartum recovery panel.
- Diet. Iron from plants is absorbed less readily than iron from meat, so vegetarian and vegan diets need more attention to it.
- Absorption. Coeliac disease and other gut conditions reduce how much iron you take in, which is one reason unexplained low iron gets investigated.
Low ferritin with a normal haemoglobin: the stage that gets missed
Iron deficiency happens in stages. Stores empty first, which shows as a falling ferritin, and only later does haemoglobin drop and the label "anaemia" appear. You can feel flat, foggy, cold and breathless for months while your full blood count still reads as normal, which is how women end up being told their bloods are fine.
This is why the two tests belong together. A normal full blood count with a ferritin of, say, 12 ug/L is a meaningful result, not a clear one. Our guide to low iron and heavy periods goes through what that pattern usually means.
What a high ferritin can mean
Ferritin also rises for reasons that have nothing to do with iron stores. It is an inflammatory marker as well as a storage protein, so infection, inflammation, recent illness, liver conditions and regular alcohol all push it up. That is why we ask you not to collect while you are unwell.
A persistently high ferritin with a high transferrin saturation is a different picture and can point to iron overload, including inherited haemochromatosis. Either way it is followed up by a doctor rather than acted on alone.
Reference ranges and what they mean
| Marker | Typical adult range | What it usually means |
|---|---|---|
| Ferritin (women) | Laboratories print a lower limit of anywhere from 15 to 30 ug/L | A ferritin under about 30 ug/L is widely treated in Australia as low iron stores in women; some laboratories use 15. Many doctors want to see well above 30 in women with symptoms, or when pregnancy is planned. |
| Serum iron | About 10 to 30 umol/L, and it varies through the day and with meals | Informative only alongside transferrin and saturation, never on its own. |
| Transferrin | Reported against the laboratory's adult range | Tends to rise when iron stores are low and fall with inflammation. |
| Transferrin saturation | Roughly 15 to 45 per cent in adults | Low saturation supports iron deficiency. Persistently high saturation prompts a look at iron overload. |
| Haemoglobin (women) | About 115 to 160 g/L | Below range is anaemia. With a low ferritin and small red cells, iron deficiency is the usual explanation. |
Ranges vary by laboratory; your report shows the range your lab uses. Typical ranges on this page are drawn from Pathology Tests Explained (RCPA) and the sources listed below.
When to do this test
Any time of day, and no fasting is needed. Two things do matter. First, do not collect while you are unwell, or for a couple of weeks after an infection, because ferritin rises with inflammation and can mask low stores. Second, if you take an iron supplement, ask whether to pause it beforehand: many laboratories suggest leaving 24 hours between a dose and collection so the serum iron reading is not artificially high. Follow whatever your request form or the collection centre advises.
If you are checking whether your iron has recovered, allow enough time for stores to rebuild before retesting. Your doctor will suggest an interval, commonly around three months.
How it works
- Order online. Either upload the request your own doctor has signed, or a KnowLuna doctor requests the test for you at no extra charge.
- Collect at an accredited centre near you, or choose a home kit or a nurse visit (options below). Any time, no fasting, and not while you are unwell.
- Results are usually ready within a few business days, explained in your account, with a doctor consult available if you want the detail talked through.
Choose how you collect
Every option is the same accredited test and the same report. Pick what suits you at checkout; the fee, if any, is added to either pathway price.
A quick draw at an accredited pathology collection centre near you. Usually under ten minutes. Included.
Lancet kit posted to you with an Express return satchel. If the lab cannot test your sample we send a replacement kit at no charge.
A near-painless device draws a small sample from the upper arm, with far fewer failed samples than a finger-prick. Express return satchel included.
A registered nurse comes to your home or workplace for a standard blood draw. Metro areas of capital cities; other locations on request.
Common questions
Is it better to have low or high ferritin?
Neither extreme is what you want. Low ferritin means your iron stores are running down, and it commonly causes fatigue, breathlessness and hair shedding. High ferritin more often reflects inflammation or recent illness than a genuine excess of iron, but a persistently high result with high transferrin saturation is investigated for iron overload.
What ferritin level is considered low in women?
Australian laboratories print a lower limit of anywhere from 15 to 30 ug/L, but a ferritin under about 30 ug/L is widely treated as low iron stores in women. Symptoms often appear before the number falls that far, so a result in the low thirties in someone who is exhausted still deserves a conversation. Your report shows your laboratory's range.
What happens if haemoglobin is high?
A mildly raised haemoglobin is often explained by dehydration on the day, altitude, or smoking. A persistently high level is investigated by a doctor, because it can reflect a bone marrow or oxygen-related cause. It is not something to interpret from a single result, and your doctor decides whether repeating it is worthwhile.
Do I need to fast for iron studies?
No. Fasting is not required for iron studies or a full blood count. Serum iron does vary through the day, so some laboratories prefer a morning collection for consistency. If you take an iron supplement, ask whether to leave 24 hours before collection, because a recent dose can lift the serum iron reading.
What is the difference between iron studies and a full blood count?
Iron studies measure iron itself: how much is stored (ferritin), how much is circulating, and how much of your carrying capacity is filled. A full blood count measures the cells, including haemoglobin and red cell size. Stores fall first, cells change later, so the two together show which stage you are at.
How much does an iron blood test cost without a referral?
Prices vary between providers. KnowLuna's iron studies and full blood count is $69, with a KnowLuna doctor requesting it at no extra charge, and an optional 20-minute results consult for +$59. There is no Medicare rebate when you order it yourself. Read ferritin and iron studies explained for more.
Sources and further reading
- Pathology Tests Explained (RCPA): ferritin
- Pathology Tests Explained (RCPA): iron studies
- World Health Organization: guideline on use of ferritin concentrations to assess iron status in individuals and populations (2020)
- Healthdirect: iron deficiency
- Healthdirect: iron studies blood test
- Better Health Channel: iron deficiency in adults
General information only, not medical advice. A test result is one input to a doctor's assessment, not a diagnosis on its own, and every abnormal result is followed up by a KnowLuna doctor. If your symptoms are severe or sudden, see a doctor promptly. Read our medical disclaimer.
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