A ferritin blood test checks the amount of ferritin in the blood. Ferritin is a protein in the body that binds to iron; most of the iron stored in the body is bound to ferritin. Ferritin is found in the liver, spleen, skeletal muscles, and bone marrow. Only a small amount of ferritin is found in the blood. The amount of ferritin in the blood shows how much iron is stored in your body.
Why It Is Done
A ferritin blood test is done to:
- Find the cause of anemia, especially iron deficiency anemia.
- See if inflammation is present.
- See if too much iron (hemochromatosis) is present.
- Check to see if iron treatment to raise or lower the iron level is working.
How To Prepare
You do not need to do anything before having this test.
How It Is Done
The health professional drawing blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure to the site and then a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
- In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
- Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.
A ferritin blood test checks the amount of ferritin in the blood. Ferritin is a protein in the body that binds to iron; most of the iron stored in the body is bound to ferritin. The amount of ferritin found in the blood is the same amount that is in the body.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
- Very high ferritin levels (greater than 1,000 ng/mL) can mean a large buildup of iron in the body (hemochromatosis). One form of this condition is passed on in families (genetic hemochromatosis). Some diseases, including alcoholism, thalassemia, and some types of anemia that cause red blood cells to be destroyed, can also cause hemochromatosis. Also, if you have many blood transfusions, this can sometimes cause the body to store too much iron (acquired hemochromatosis).
- High ferritin levels may also be caused by liver disease (cirrhosis or hepatitis), Hodgkin's disease, leukemia, infection, inflammatory conditions (such as arthritis or lupus), or a diet that is too high in iron.
- Too much iron in body organs, such as the pancreas or heart, can affect how the organ works.
Low ferritin levels often mean an iron deficiency is present. This can be caused by long-term (chronic) blood loss from heavy menstrual bleeding, pregnancy, not enough iron in the diet, or bleeding inside the intestinal tract (from ulcers, colon polyps, colon cancer, hemorrhoids, or other conditions). In rare cases, too much iron may be lost through the skin (because of a disease such as psoriasis) or in the urine.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
- Having a blood transfusion in the past 4 months.
- Being a female athlete doing sports that change the menstrual cycle.
- Having conditions that cause inflammation in the body, such as from illness or from a surgery.
- Having a radioactive scan in the past 3 days.
- Taking medicines, such as birth control pills and antithyroid medicines.
- Age. Older adults may have a higher ferritin value.
- Eating a diet high in red meats.
What To Think About
- A ferritin test is often done with other tests to check the amount of iron in the blood, especially the iron and iron-binding capacity levels. For more information, see the topic Iron (Fe).
- A bone marrow biopsy can check the amount of iron stored in the bone marrow. For more information, see the topic Bone Marrow Aspiration and Biopsy.
- Because inflammation in the body can cause high ferritin levels, a test result that is slightly high does not always mean a buildup of iron (hemochromatosis) is present.
Other Works Consulted
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||Joseph O'Donnell, MD - Hematology, Oncology|
|Last Revised||August 3, 2010|