What is iron called on a blood test?
Iron appears on blood tests primarily as "ferritin" (stored iron) and "serum iron" (circulating iron). Additional tests like TIBC, transferrin saturation, and transferrin help provide a complete picture of your iron status.
Understanding Iron Test Names on Your Lab Results
When you receive your blood test results, you might notice that "iron" isn't simply listed as "iron." Instead, laboratories use several specific terms to measure different aspects of iron in your body. Understanding these terms helps you better interpret your results and have more informed conversations with your healthcare provider.
The most common iron-related tests you'll see on lab reports include ferritin, serum iron, total iron-binding capacity (TIBC), transferrin saturation, and sometimes transferrin itself. Each test provides unique information about how your body stores, transports, and uses iron.
Primary Iron Tests and Their Lab Names
Ferritin: Your Iron Storage Indicator
Ferritin is the most commonly ordered iron test and appears on lab reports as "Ferritin" or sometimes "Serum Ferritin." This protein stores iron in your cells and releases it when your body needs it. Think of ferritin as your body's iron savings account - it reflects how much iron you have stored for future use.
Normal ferritin ranges vary by age and sex, but generally fall between 12-300 ng/mL for men and 12-150 ng/mL for women. Low ferritin levels typically indicate iron deficiency, while high levels might suggest iron overload or inflammation.
Serum Iron: Circulating Iron in Your Blood
"Serum Iron" or "Iron, Serum" measures the amount of iron currently circulating in your bloodstream. This represents only a small fraction of your total body iron and can fluctuate throughout the day, typically being highest in the morning.
Normal serum iron ranges are approximately 60-170 mcg/dL for men and 50-150 mcg/dL for women. However, serum iron alone doesn't provide a complete picture of your iron status, which is why doctors often order additional tests.
TIBC and Transferrin: Iron Transport Capacity
Total Iron-Binding Capacity (TIBC) measures how much iron your blood can carry. It's listed as "TIBC" or "Total Iron Binding Capacity" on lab reports. This test indirectly measures transferrin, the main protein that transports iron through your bloodstream.
Some labs directly measure "Transferrin" instead of or in addition to TIBC. Normal TIBC ranges from 250-450 mcg/dL. When iron stores are low, your body produces more transferrin to capture available iron, causing TIBC to increase.
Additional Iron-Related Tests
Transferrin Saturation: The Iron Utilization Percentage
Transferrin saturation, often abbreviated as "TSAT" or listed as "Iron Saturation %," calculates the percentage of transferrin that's carrying iron. It's determined by dividing serum iron by TIBC and multiplying by 100.
Normal transferrin saturation ranges from 20-50%. Low saturation suggests iron deficiency, while high saturation might indicate iron overload conditions like hemochromatosis.
Less Common Iron Tests
Other iron-related tests you might encounter include:
- Unsaturated Iron-Binding Capacity (UIBC): Measures how much more iron your transferrin can carry
- Soluble Transferrin Receptor (sTfR): Helps distinguish between iron deficiency and anemia of chronic disease
- Hepcidin: A hormone that regulates iron absorption, though not routinely tested
How Iron Tests Appear on Different Lab Reports
Laboratory reports can vary in format and terminology. Here's how iron tests commonly appear on different types of lab reports:
- Hospital labs: Often use full names like "Ferritin, Serum" or "Iron, Total"
- Commercial labs: May use abbreviations like "FER" for ferritin or "FE" for iron
- Electronic health records: Sometimes group iron tests under "Iron Studies" or "Iron Panel"
Understanding these variations helps you locate and track your iron results across different healthcare providers and testing facilities.
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Why Multiple Iron Tests Matter
Doctors rarely rely on a single iron test because each provides only part of the picture. For example, ferritin can be falsely elevated during inflammation or infection, even when iron stores are actually low. Similarly, serum iron fluctuates throughout the day and with meals.
A comprehensive iron panel typically includes ferritin, serum iron, TIBC, and transferrin saturation. This combination helps distinguish between different causes of anemia and identifies both iron deficiency and iron overload conditions. Regular monitoring of these biomarkers can help you maintain optimal iron levels for energy, immune function, and overall health.
Interpreting Your Iron Test Results
When reviewing your iron tests, consider these patterns:
- Iron deficiency: Low ferritin, low serum iron, high TIBC, low transferrin saturation
- Iron overload: High ferritin, high serum iron, low or normal TIBC, high transferrin saturation
- Anemia of chronic disease: Low or normal serum iron, low TIBC, normal or high ferritin
Remember that reference ranges can vary between laboratories, and optimal ranges might differ from standard reference ranges. Factors like age, sex, pregnancy, and altitude can all affect what's considered normal for you.
When to Test Your Iron Levels
Consider iron testing if you experience symptoms like fatigue, weakness, pale skin, shortness of breath, or frequent infections. Women with heavy menstrual periods, vegetarians and vegans, frequent blood donors, and endurance athletes should monitor their iron status regularly.
For accurate results, most iron tests require fasting for 12 hours, and it's best to schedule testing in the morning when iron levels are typically highest. Avoid iron supplements for at least 24-48 hours before testing unless your doctor instructs otherwise.
If you have existing blood test results that include iron markers, you can get a comprehensive analysis of your iron status and personalized recommendations through SiPhox Health's free blood test upload service. This AI-powered analysis helps you understand your iron levels in the context of your overall health profile.
Taking Action on Your Iron Results
Once you understand what iron is called on your blood test and receive your results, work with your healthcare provider to address any imbalances. Treatment might include dietary changes, iron supplementation, or addressing underlying conditions affecting iron absorption or utilization.
Remember that both too little and too much iron can be harmful. While iron deficiency is more common, especially in women, iron overload can damage organs over time. Regular testing helps you maintain the right balance for optimal health and vitality.
References
- Camaschella, C. (2019). Iron deficiency. Blood, 133(1), 30-39.[Link][DOI]
- Knovich, M. A., Storey, J. A., Coffman, L. G., Torti, S. V., & Torti, F. M. (2009). Ferritin for the clinician. Blood Reviews, 23(3), 95-104.[Link][PubMed][DOI]
- Dignass, A., Farrag, K., & Stein, J. (2018). Limitations of serum ferritin in diagnosing iron deficiency in inflammatory conditions. International Journal of Chronic Diseases, 2018, 9394060.[Link][PubMed][DOI]
- Lopez, A., Cacoub, P., Macdougall, I. C., & Peyrin-Biroulet, L. (2016). Iron deficiency anaemia. The Lancet, 387(10021), 907-916.[DOI]
- Pasricha, S. R., Tye-Din, J., Muckenthaler, M. U., & Swinkels, D. W. (2021). Iron deficiency. The Lancet, 397(10270), 233-248.[DOI]
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Frequently Asked Questions
How can I test my ferritin at home?
You can test your ferritin at home with SiPhox Health's Core Health Program. This CLIA-certified program includes ferritin testing along with other essential biomarkers, providing lab-quality results from the comfort of your home.
What's the difference between ferritin and serum iron?
Ferritin measures your stored iron reserves, like a savings account, while serum iron measures the iron currently circulating in your blood. Ferritin is generally more stable and reliable for assessing overall iron status, while serum iron can fluctuate throughout the day.
Why does my doctor order multiple iron tests instead of just one?
Multiple iron tests provide a complete picture of your iron status. Each test measures a different aspect - storage (ferritin), circulation (serum iron), and transport capacity (TIBC/transferrin). Together, they help distinguish between iron deficiency, iron overload, and other conditions affecting iron metabolism.
What is a normal ferritin level?
Normal ferritin ranges vary by lab but typically fall between 12-300 ng/mL for men and 12-150 ng/mL for women. However, optimal levels for health and energy are often in the middle of these ranges, around 50-150 ng/mL, depending on individual factors.
Can I have normal hemoglobin but still be iron deficient?
Yes, iron deficiency develops in stages. Your iron stores (ferritin) deplete first, before hemoglobin drops. This is why testing ferritin is important - it can catch iron deficiency early, before it progresses to iron deficiency anemia with low hemoglobin.
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