Ferritin measures the amount of iron-storage protein circulating in the blood, which usually tracks the body's iron stores. It is ordered with iron studies when a clinician is assessing iron status. It does not confirm or rule out a condition on its own, and the range printed on your report applies.
Ferritin is the most commonly used marker of iron stores, but it is not a pure measure of iron. It behaves as an acute-phase protein, so inflammation and infection can raise it while iron stores stay low.
What the test measures
Ferritin is a protein that stores iron inside cells, keeping it in a form that is available but not toxic. A small amount of ferritin circulates in the blood, and that is what the test measures. The circulating level roughly follows the amount of iron stored in the body, which is why it is used as an estimate of iron stores.
The estimate is not exact. Ferritin rises with inflammation, infection, liver injury, and some other conditions, because it is part of the body's acute-phase response. In those situations a value inside the printed range may still sit above a person's true iron stores, and a value above the range may have nothing to do with iron loading.
Ferritin is measured by immunoassay, and different methods and calibrations can produce different values on the same sample.
Why it may be ordered
- With a blood count, when anaemia is being assessed and red cells are smaller or paler than expected.
- When iron deficiency or iron loading is a question a clinician wants to explore.
- As part of an iron studies panel with serum iron and a binding measurement.
- When inflammation or liver disease is present, to see how ferritin behaves in that context.
- To follow a known value over time.
It is not a universal screening test, and a result inside the printed range does not settle every question about iron. The test is one line in an assessment that includes the blood count, the other iron studies, and the history.
The unit on your report
| What you may see | What it means |
|---|---|
| Ferritin, serum ferritin | The test name. Some reports add a note that it reflects iron stores. |
| ng/mL | Nanograms per millilitre, the unit most reports use. |
| ug/L | Micrograms per litre, the same scale as ng/mL. The two are equivalent. |
| Iron studies, iron panel | The group heading some reports use for ferritin, serum iron, and binding measurements. |
Why this page does not print a range
Ferritin ranges differ by laboratory and method, and they can depend on age and sex, because iron stores differ across the lifespan. Some laboratories print a single lower limit, and some print a range with an upper limit. The population the interval was built from also matters, and so does the clinical context.
The range or limit printed on the report that produced your value is the one that applies. Doctano keeps that printed range with the result and does not replace it with a general range. Where a report prints a comment about inflammation or a repeat sample, Doctano keeps that with the result as well.
What a high value can mean
A higher ferritin can be associated with increased iron stores, including inherited iron-loading conditions and iron loading from repeated transfusions. It can also rise with inflammation, infection, liver disease, and some blood conditions, none of which is a matter of iron stores. High intake of iron can contribute as well.
Because the possible contributors are so different, a high ferritin is read with serum iron, transferrin saturation, CRP where measured, liver results, and the history. A high value is not a diagnosis and does not by itself show that iron is overloaded.
What a low value can mean
A lower ferritin usually means iron stores are depleted, and it is often one of the earlier changes when iron is being lost faster than it is replaced. Possible contributors include blood loss, reduced absorption from the gut, and increased demand during pregnancy or growth.
It is read with the blood count and the history, and a value inside the printed range does not exclude depleted stores when inflammation is present.
What can move the value
- Inflammation and infection. Ferritin rises as part of the acute-phase response, independently of iron stores.
- Liver disease. Liver injury releases ferritin and can raise the value.
- Pregnancy. Iron demand rises and ferritin usually falls across pregnancy.
- Menstruation. Regular blood loss lowers iron stores and ferritin over time.
- Recent iron intake. Iron taken shortly before the sample can raise the value for a period.
- Assay method. Different immunoassays and calibrations can give different values on the same sample.
What to compare it with
Read ferritin with serum iron, total iron-binding capacity, and transferrin saturation where they are printed. The combination describes how iron is being stored, carried, and delivered, and it separates iron loading from inflammation better than ferritin alone. CRP adds context when inflammation is a possibility.
The blood count matters too: haemoglobin, MCV, and MCH show whether red cell formation has been affected. Vitamin B12 and folate can matter when anaemia is being assessed, because more than one contributor can be present. The most useful comparison is the previous ferritin from the same laboratory.
How to see the trend
Doctano reads the ferritin value, its unit, and the reference range printed on the report. It keeps the range with the result, normalizes the marker name across laboratories, and places the value on the profile's timeline. Each point still opens the report it came from, so the original page can be checked.
Ferritin moves with inflammation as well as with iron, so a single point can be misleading. Verify the value, the unit, and the date against the original report, and look at the points around it before treating a change as real.
What this page is not
This page explains the test in general. It does not interpret your result, diagnose a condition, or recommend treatment. It is not medical advice. Verify the value and the unit against the original report, and discuss the result with a qualified professional.