Measures level of ferritin to assess iron deficiency or iron overload.
About the Test
Purpose of the test
The purpose of a ferritin test is to determine whether your body is storing a normal amount of iron.
The result of a ferritin test may be interpreted alone, but most often it is evaluated at the same time as blood tests, liver function tests, or iron studies. Ferritin testing is used to screen for, diagnose, or monitor certain conditions.
Ferritin testing is used as a screening tool along with other blood tests to look for low levels of iron or iron deficiency, before symptoms develop. Screening with a ferritin test is typically only used in patients who are at an especially high risk for iron deficiency, including:
- Female adolescents who are underweight, experience heavy blood loss during menstruation, or who do not get enough iron in their diet
- People who are pregnant
Diagnostic testing aims to find the cause of a patient’s symptoms. A ferritin test can help to diagnose or rule out the following conditions:
- Iron deficiency anemia: If your body’s iron levels are consistently low, iron deficiency can progress to anemia. Low iron levels in the blood reduce production of red blood cells, which affects the body’s ability to deliver enough oxygen to muscles and organs.
- Iron overload: High levels of iron are referred to as iron overload or hemochromatosis. Your body does not have a natural way to get rid of extra iron and it will deposit it in body tissues, like the liver, heart, and pancreas. Iron overload can cause serious damage to your organs.
- Liver disease: A large amount of our iron is stored in ferritin proteins in the liver. When the liver is damaged or diseased, iron and ferritin can leak from the liver into the blood. Ferritin testing can help diagnose liver conditions such as alcohol abuse, cirrhosis, and Hepatitis B and C infection.
- Restless legs syndrome (RLS): RLS is characterized by uncomfortable feelings in the limbs and a strong urge to move them, especially when sitting or laying. Ferritin testing can determine whether iron deficiency may be contributing to RLS symptoms.
- Adult-onset still disease (AOSD): AOSD is a rare condition that causes joint pain and swelling, fevers, rash, and high levels of ferritin.
Doctors monitor ferritin levels in people receiving iron supplementation therapy for iron deficiency anemia. Repeat testing of ferritin and other blood levels allow doctors to determine whether the treatment is working and when a patient can discontinue treatment.
Patients with chronic conditions like cancer, liver disease, or kidney disease may also have regular ferritin testing as part of regular blood work to check for signs of iron overload or iron deficiency that may require treatment.
What does the test measure?
Ferritin testing measures the amount of ferritin that is circulating in the blood. Ferritin is a protein that stores iron, an essential mineral that is needed for healthy growth and development.
Iron cannot exist on its own in the body. Instead, iron binds to a protein called transferrin, which transports it to different parts of the body. Extra iron is stored in ferritin, which is usually concentrated in the liver and the cells of the immune system.
When the body uses stored iron, a metabolic process separates iron from the ferritin inside the cell. In this process, a small amount of ferritin leaves the cell and moves into the blood. A ferritin test measures the amount of ferritin in the blood because it reflects the total amount of iron that is stored in your body.
When should I get a ferritin test?
You may need a ferritin test if you have symptoms of iron deficiency or iron overload.
Iron deficiency can cause the following symptoms:
- Feeling tired frequently over a long period of time
- Shortness of breath
- Rapid or irregular heartbeat
- Pale skin
- Swelling of the tongue
- Restless legs syndrome
- Pica, or unusual cravings for non-food items like ice, clay, soil, or paper.
Symptoms of iron overload can vary widely and depend upon which organs are affected and how long excess iron has been collecting in the body. They may include the following:
- Joint pain
- Fatigue or weakness
- Grey or bronze colored skin
- Abdominal pain
- Irregular heart beat
If your doctor has recommended that you take dietary iron supplements, you may receive periodic ferritin testing to assess your response and guide further treatment.
Finding a Ferritin Test
How to get tested
A ferritin test is performed on a blood sample that is collected from a vein in your arm at a doctor’s office or laboratory. Ferritin may be tested on its own, or one blood sample may be used to test multiple iron values in addition to ferritin, such as iron, total iron-binding capacity (TIBC), and transferrin saturation test.
You can talk to your doctor about what kind of testing is appropriate for your situation and the health condition you are assessing with the ferritin test. There are also options for testing your ferritin levels without seeing your doctor first. However, it’s important to share your results with your doctor and health care team to discuss whether additional testing or treatment is needed.
Can I take the test at home?
At-home ferritin testing is available. Testing your ferritin level at home involves collecting a fingerstick blood sample and mailing it to a laboratory for analysis. At-home test kits include options to test your ferritin level alone or as part of an iron studies panel, which includes multiple measurements.
You can purchase an at-home ferritin testing kit from a number of online retailers. After you receive your results, it’s important to share them with your doctor for follow-up instructions. If you have abnormal results on an at-home ferritin test, your doctor will likely recommend performing a blood draw and repeating the test to confirm the results.
How much does the test cost?
The cost of a ferritin test depends upon many factors including where you have the blood sample drawn, whether ferritin is tested alone or in an iron studies panel, and whether you have health insurance coverage.
If your doctor orders the test, your health insurance may cover the cost of the blood draw, laboratory fees, and a doctor’s office visit, with the exception of any copays or deductibles. Contact your doctor or health insurance provider to obtain the most accurate information about your out-of-pocket costs.
If you choose to pursue ferritin testing without a doctor’s prescription, you will likely have to pay any costs associated with the blood sample collection and analysis yourself. The laboratory can provide a breakdown of costs associated with their services and tests.
Taking a Ferritin Test
A ferritin test requires a small sample of blood. A phlebotomist in a doctor’s office or laboratory will collect a sample from a vein in your arm.
Before the test
Although ferritin concentration is not affected by food, other iron studies tests may require special preparation. For example, if your blood test will measure your iron level or your transferrin saturation level in addition to your ferritin level, you may be asked to fast, which means avoiding food or drinks besides water for up to 12 hours before the test.
During the test
A blood sample for a ferritin test is usually collected from a vein in the forearm. During a blood draw, the phlebotomist may place a band around your arm to create pressure and increase blood flow in the vein. Your arm will be cleaned with an antiseptic wipe before a needle is inserted into the arm. Drawing blood may take several minutes and you may feel a pinch when the needle goes in or out.
After the test
After your blood draw is finished, a cotton swab or bandage will be applied to stop any continued bleeding. Serious effects are uncommon, but there may be tenderness in your arm. Some bruising around the puncture site is also possible.
You can return to driving and other normal activities once the test is complete. If you are required to fast, you may want to bring something to eat after the test is finished.
Ferritin Test Results
Receiving test results
After the lab receives your blood sample, it may take a few business days before you or your doctor receives the ferritin test results. The report with your results may be sent in the mail or electronically. If your test was ordered by your doctor, a member of your health care team may contact you to report your ferritin level.
Interpreting test results
A ferritin test is reported as a number that represents nanograms of ferritin per milliliter of blood, or ng/mL.
The doctor will use a reference range to interpret your ferritin level as low, normal, or high. The reference range is the normal range for someone of your age, sex, and overall health context. In general, ferritin levels are higher as people age, in males, and in people who are taking contraceptives.
Reference ranges also vary from laboratory to laboratory. Your test results report will provide information on the reference ranges used by the laboratory that analyzed your blood, and you can ask your doctor how the ranges apply to your specific situation.
Ferritin levels are often compared with the results of other iron tests when evaluating a patient for an iron metabolic disorder or another condition.
Lower than normal results
A low ferritin level likely means you may have an iron deficiency. If the body does not have enough stored iron, it can affect the production of healthy red blood cells and cause iron deficiency anemia.
In early stages of iron deficiency anemia, your body may have a low amount of ferritin but a normal amount of iron in the blood and will still be able to make healthy red blood cells. You may have few or no symptoms of anemia at this point.
If iron deficiency progresses, ferritin levels and blood iron levels fall as your body uses up stored iron. The body will try to compensate and increase the amount of transferrin to try to transport iron, even if the level of stored iron is very low. The doctor will compare serum ferritin, serum iron, total iron-binding capacity (TIBC) and transferrin saturation to determine the severity of iron deficiency anemia.
Higher than normal results
A high ferritin level can indicate iron overload. Iron overload is most commonly associated with hemochromatosis, a condition where your body absorbs more iron that it needs.
Elevated ferritin levels can also be due to something other than iron overload. Ferritin is an important marker of inflammation in the body, so ferritin levels can be elevated anytime a person has an inflammatory condition, such as an underlying infection. Other conditions that cause elevated ferritin include:
- Alcohol use disorder
- Anemia not caused by iron deficiency
- Hyperthyroidism, also called overactive thyroid
- Adult Still’s disease
- Liver disease including cirrhosis
Are test results accurate?
Ferritin testing as part of an iron studies panel is generally considered accurate. As with any laboratory test, there is the potential for errors to occur. However, laboratory technicians take many steps to ensure that strict protocols are followed and results are accurate.
Ferritin testing is widely considered the most accurate method for determining whether a person has iron deficiency unless a person has an inflammatory condition such as an autoimmune disease, a cardiovascular disease, or diabetes. This is because inflammation in the body affects the result of a ferritin test.
Talk with your doctor about whether inflammation or other factors may affect the results of your ferritin test.
Do I need follow-up tests?
Repeated ferritin testing and iron studies are usually recommended when an abnormal ferritin level is found. Treatments are available for both iron deficiency anemia and iron overload. Monitoring ferritin levels can be a useful assessment of a person’s response to treatment.
An elevated ferritin level usually leads to further diagnostic testing to check for hemochromatosis. A genetic test can confirm hereditary hemochromatosis by checking for mutations of the HFE genes. A liver biopsy can help doctors find out how much excess iron is in the liver and assess the severity of liver damage.
Questions for your doctor about test results
To better understand the results of your ferritin test, you can ask your doctor questions such as:
- Are my ferritin levels normal or abnormal?
- How do my ferritin levels compare with other iron studies?
- What could be causing abnormal ferritin levels?
- What other tests should be performed?
- Should I recheck my ferritin levels and if so, how soon?