Can this result diagnose a condition on its own?

No. A laboratory result should be interpreted with related tests, symptoms, medical history, and the reference information on the report.

Which reference range should I use?

Use the reference interval provided by the laboratory that performed the test. Clinical decision cutoffs, when relevant, are shown separately.

When should I discuss the result with a healthcare professional?

Professional assessment is appropriate when a result is markedly outside the reference interval, serious symptoms are present, an abnormality persists or recurs, or follow-up has been recommended.

Information about a laboratory test

Serum Iron: What Does This Blood Test Measure?

Measures the amount of iron circulating in the blood, largely bound to transferrin.

Test summary

Test name: Serum Iron
Abbreviations: Fe, Serum Iron
Category: Iron Metabolism
Panel: Iron Studies
Specimen: Serum
Common units: µg/dL, µmol/L

What does the test measure?

Measures the amount of iron circulating in the blood, largely bound to transferrin.

Why is the test ordered?

Used with ferritin, TIBC or transferrin, and transferrin saturation to assess patterns of iron status.

Information about a low result

Low serum iron can occur with iron deficiency but is also influenced by inflammation and normal variation over the course of the day.

Information about a high result

High serum iron can occur with iron overload and some liver or hematologic conditions, but it is not sufficient by itself to determine total body iron status.

Reference and clinical context

Use the reference interval printed on your own laboratory report first. Reference intervals may vary by laboratory, method, unit, age, sex, pregnancy, specimen, and other conditions. Numeric records in this workbook are explicitly labeled as either source-based example reference intervals or clinical decision cutoffs.

Reference range 1

>= 59 – <= 158 µg/dL

Population: Adults
Sex: Male
Specimen: Serum

Example reference interval

MedlinePlus example; morning/fasting context may affect results.

Reference range 2

>= 37 – <= 145 µg/dL

Population: Adults
Sex: Female
Specimen: Serum

Example reference interval

MedlinePlus example; morning/fasting context may affect results.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

Serum iron can vary during the day and may be higher in the morning. It does not directly measure iron stores.

Related specialties

Internal Medicine
Hematology
Gastroenterology

Frequently asked questions

More information about this test

Sources

Iron Tests — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2024 · Serum iron, transferrin, TIBC, ferritin; combined interpretation · Verified: Aug 11, 2026
Serum iron test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2026 · Example adult serum iron, TIBC and iron saturation ranges · Verified: Aug 11, 2026