Iron Tests - Understand the Test & Your Results

What are iron tests?
Iron tests measure different substances in the blood to check iron levels in your body. Iron is a mineral that's essential for making red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. Iron is also important for healthy muscles, bone marrow, and organ function. Iron levels that are too low or too high can cause serious health problems.
Different types of iron tests include:
Serum iron test, which measures the amount of iron in the blood
Transferrin test, which measures transferrin, a protein that moves iron throughout the body
Total iron-binding capacity (TIBC), which measures how well iron attaches to transferrin and other proteins in the blood
Ferritin blood test , which measures how much iron is stored in the body
Some or all of these tests are often ordered at the same time.
Other names: Fe tests, iron indices
What are they used for?
Iron tests are most often used to:
Check if your iron levels are too low, a sign of anemia
Diagnose different types of anemia
Check if your iron levels are too high, which could be a sign of hemochromatosis . This is a rare genetic disorder that causes too much iron to build up in the body.
See if treatments for iron deficiency (low iron levels) or excess iron (high iron levels) are working
Why do I need an iron test?
You may need testing if you have symptoms of iron levels that are too low or too high.
Symptoms of iron levels that are too low include:
Pale skin
Fatigue
Weakness
Dizziness
Shortness of breath
Rapid heartbeat
Symptoms of iron levels that are too high include:
Joint pain
Abdominal pain
Lack of energy
Weight loss
What happens during an iron test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
Your health care provider may ask you to fast (not eat or drink) for 12 hours before your test. The test is usually done in the morning. If you have any questions about how to prepare for your test, talk to your health care provider.
Are there any risks to iron tests?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
If one or more iron test results show your iron levels are too low, it may mean you have:
Iron deficiency anemia, a common type of anemia. Anemia is a disorder in which your body doesn't make enough red blood cells.
Another type of anemia
Thalassemia , an inherited blood disorder that causes the body to make fewer than normal healthy red blood cells
If one or more iron test results show your iron levels are too high, it may mean you have:
Hemochromatosis, a disorder that causes too much iron to build up in the body
Lead poisoning
Liver disease
Most conditions that cause too little or too much iron can be successfully treated with iron supplements, diet, medicines, and/or other therapies.
If your iron test results are not normal, it does not necessarily mean you have a medical condition needing treatment. Some medicines, including birth control pills and estrogen treatments, can affect iron levels. Iron levels may also be lower for women during their menstrual cycles .
If you have questions about your results, talk to your health care provider.
Learn more about laboratory tests, reference ranges, and understanding results .
Is there anything else I need to know about iron tests?
Your health care provider may order other blood tests to help check your iron levels. These include:
Hemoglobin test
Hematocrit test
Complete blood count
Mean corpuscular volume
References
American Society of Hematology [Internet]. Washington D.C.: American Society of Hematology; c2019. Iron- Deficiency Anemia; [cited 2019 Dec 3]; [about 3 screens]. Available from: https://www.hematology.org/Patients/Anemia/Iron-Deficiency.aspx
Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2019. Ferritin; [updated 2019 Nov 19; cited 2019 Dec 3]; [about 2 screens]. Available from: https://labtestsonline.org/tests/ferritin
Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2019. Iron Tests; [updated 2019 Nov 15; cited 2019 Dec 3]; [about 2 screens]. Available from: https://labtestsonline.org/tests/iron-tests
Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co., Inc.; c2019. Iron; [updated 2018 Nov; cited 2019 Dec 3]; [about 3 screens]. Available from: https://www.merckmanuals.com/home/disorders-of-nutrition/minerals/iron
National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [cited 2019 Dec 3]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Thalassemias; [cited 2019 Dec 3]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/thalassemias
University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2019. Health Encyclopedia: Iron and Total Iron-Binding Capacity; [cited 2019 Dec 3]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=iron_total_iron_binding_capacity
UW Health [Internet]. Madison (WI):University of Wisconsin Hospitals and Clinics Authority; c2021. Iron (Fe) Test; [cited 2021 Aug 9]; [about 3 screens]. Available from: https://patient.uwhealth.org/healthwise/article/hw41550