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
- 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.
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