Iron blood test
Serum iron
In short
A typical adult iron result is 37 to 145 µg/dL for women and 59 to 158 µg/dL for men. A high iron on its own is often from a recent meal, iron supplements or the time of day. If it stays high and its carrier protein is also very full, doctors may check for iron overload. Always read your result against the range printed on your own report.
The iron traveling in the blood when the sample was taken.
Serum iron is the iron carried in the liquid part of blood, bound to a protein called transferrin. It swings through the day and after meals, so one result says little on its own. Ferritin, which reflects iron stores, says much more, so doctors read the two together.
Is my Iron high or low?
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Typical range
| For | Range | Unit |
|---|---|---|
| Female | 37–145 | µg/dL |
| Male | 59–158 | µg/dL |
| Female | 6.6–26 | µmol/L |
| Male | 10.6–28.3 | µmol/L |
Typical ranges for adults. Labs differ a little, so the range printed next to your result is the one to go by.
If your Iron is high
A high iron on its own is often from a recent meal, iron supplements or the time of day. If it stays high and its carrier protein is also very full, doctors may check for iron overload.
Common reasons
- Iron supplements or iron-rich food in the hours before the test
- A morning blood draw, when iron tends to be highest
- Recent iron infusions or blood transfusions
- An inflamed liver (hepatitis)
- Red cells breaking down faster than usual (hemolysis)
- Less often: hemochromatosis, an inherited condition that stores too much iron
If your Iron is low
A low iron can mean low iron stores, or inflammation that locks iron away for a while. Ferritin usually shows which is more likely.
Common reasons
- An afternoon or evening draw, when iron tends to be lower
- A recent infection, illness or other inflammation
- Heavy menstrual periods
- Not enough iron from food
- Pregnancy, when the body needs more iron
- Poor iron absorption, as with celiac disease or stomach surgery
- Less often: slow, hidden bleeding from the stomach or bowel
What can throw it off
Iron swings a lot through the day and rises after meals and iron supplements, so timing matters.
Questions to take to your appointment
- 1Should my ferritin be checked to see my iron stores?
- 2Could the time of day, a meal or supplements explain this?
- 3Should it be repeated in the morning before I eat?
Read together with
Doctors rarely read Iron alone. These usually sit next to it.
- FerritinThe body's iron-storage protein; its level mirrors your iron reserves.
- TIBCHow much iron the blood's iron carrier could hold.
- Transferrin saturationHow full the blood's iron carrier is, as a percent.
- HemoglobinThe protein in red blood cells that carries oxygen.
- MCVThe average size of your red blood cells.
Quick answers
What is the iron blood test?
Iron: The iron traveling in the blood when the sample was taken. Serum iron is the iron carried in the liquid part of blood, bound to a protein called transferrin. It swings through the day and after meals, so one result says little on its own. Ferritin, which reflects iron stores, says much more, so doctors read the two together.
What is a normal iron level?
For most adults, iron is typically 37 to 145 µg/dL for women and 59 to 158 µg/dL for men. Some countries print it in µmol/L, so check the unit first. Labs differ a little, so the range printed next to your result is the one to go by.
What does a high iron mean?
A high iron on its own is often from a recent meal, iron supplements or the time of day. If it stays high and its carrier protein is also very full, doctors may check for iron overload. Common reasons include iron supplements or iron-rich food in the hours before the test; a morning blood draw, when iron tends to be highest; recent iron infusions or blood transfusions; and an inflamed liver (hepatitis). A doctor reads it together with your other results and how you feel.
What does a low iron mean?
A low iron can mean low iron stores, or inflammation that locks iron away for a while. Ferritin usually shows which is more likely. Common reasons include an afternoon or evening draw, when iron tends to be lower; a recent infection, illness or other inflammation; heavy menstrual periods; and not enough iron from food.
What can affect my iron result?
Iron swings a lot through the day and rises after meals and iron supplements, so timing matters.
What should I ask my doctor about my iron?
Questions worth taking to the appointment: Should my ferritin be checked to see my iron stores? Could the time of day, a meal or supplements explain this? Should it be repeated in the morning before I eat?
What this page can’t do
It reads each number on its own.
Doctors read results together — ALT with AST, ferritin with hemoglobin, TSH with free T4. A pattern says more than any single flag.
It doesn't know you.
Your age, your medicines, how you feel and your last result all change what a number means.
It doesn't remember.
Close this page and your results are gone. That's on purpose: nothing was ever sent to us.
We also make Vita: Health Coach, an app for those parts. It reads your whole report with your medicines and history in mind, answers follow-up questions in plain words, and keeps your reports in one place — for you and for the people you look after.
Vita: Health Coach on the App StoreSources
- MedlinePlus — Serum iron test
- MedlinePlus — Iron tests
- Merck Manual Professional — Iron deficiency anemia
Stuck on a word? See the medical words. How we choose our sources. More about Vita Health Coach.