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

High Transferrin Saturation (TSAT): What Does It Mean?

A high transferrin saturation can occur in patterns of iron overload, but a single result does not establish a diagnosis.

Test summary

Test name: Transferrin Saturation (TSAT)
Abbreviations: TSAT, Iron Saturation
Category: Iron Metabolism
Panel: Iron Studies
Specimen: Serum
Common units: %

What does the test measure?

Expresses the percentage of transferrin iron-binding sites that are occupied by iron; it is related to serum iron and iron-binding capacity.

Why is the test ordered?

Used to assess the availability of circulating iron and to help interpret patterns of iron deficiency or iron overload.

Information about a low result

A low transferrin saturation can occur when iron availability is reduced and is interpreted together with other iron studies.

Information about a high result

A high transferrin saturation can occur in patterns of iron overload, but a single result does not establish a diagnosis.

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

>= 20 – <= 50 %

Population: Adults
Sex: Male
Specimen: Serum

Example reference interval

MedlinePlus iron saturation example.

Reference range 2

>= 15 – <= 45 %

Population: Adults
Sex: Female
Specimen: Serum

Example reference interval

MedlinePlus iron saturation example.

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

A high TSAT alone does not diagnose iron overload; ferritin, clinical history, and further evaluation when appropriate are also needed.

Related specialties

Internal Medicine
Hematology
Gastroenterology

Frequently asked questions

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