Iron Transferrin Saturation (TISS) or Transferrin Saturation
This test measures how much iron is bound to a protein called transferrin in your blood, helping assess iron availability for your body’s needs.
["Evaluates iron utilization and potential iron deficiency or overload."]
Key facts at a glance
- LOINC
- 10761-5
- Short code
- Iron Tiss Other Stn
- Synonyms
- Iron Tiss Other Stn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 60
- Ref high
- 170
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- xxx-stain
- CPT
- 83540
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Matters
Iron transferrin saturation is important because it helps doctors diagnose conditions like iron deficiency anemia or hemochromatosis (iron overload). Low levels may indicate poor iron absorption or storage, while high levels could signal excess iron storage in the body.
How the Test Works
Your blood sample is tested to determine the percentage of transferrin protein that is saturated with iron. This is done through a blood draw, typically collected in a standard tube for serum or plasma analysis.
What to Expect Before the Test
No special preparation is needed for this test. You may eat and drink normally on the day of your appointment. If you’re on blood thinners or have a history of bleeding disorders, let your healthcare provider know.
Possible Results and Next Steps
Results are usually reported as a percentage. Low transferrin saturation often suggests iron deficiency, while very high levels may indicate hemochromatosis or other conditions. Your doctor will discuss results with you and may recommend further testing or adjustments to your diet or treatment plan.
Reference range
NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A
Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
TISS
Frequently asked questions
What does a low transferrin saturation mean?
A high transferrin saturation is often associated with hemochromatosis, a condition where the body absorbs too much iron, leading to organ damage over time. It may also be seen in certain chronic diseases or medications.
No specific restrictions apply, but if you’re taking iron supplements or have recent blood loss (e.g., heavy periods, injuries), inform your healthcare provider, as it may affect results.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy