What Is a Ferritin Blood Test?
A ferritin test measures the amount of a blood protein called ferritin, which stores iron. Think of your body as a kitchen pantry. Most of it is stocked with food you use every day. But you keep some items in there for thelong term—an extra box of pasta or a can of beans to have on hand when supplies get low.
Your body stores iron the same way. It uses some of the iron it gets from food right away to make oxygen in your blood. But it also keeps some iron on hand for times when you don't get enough from the food you eat.
The iron is stored in a protein called ferritin. To see how much is in your body, your doctor might order a ferritin blood test. The test also can offer clues on conditions not linked to your iron levels. You might get other blood tests as well, including one that looks directly for iron in your bloodstream.
Ferritin vs. iron
Iron is a mineral you get from food, while ferritin is a blood protein that stores iron. But testing for ferritin is one way your doctor tells whether you're storing a healthy amount of iron in your body.
Why Do I Need a Ferritin Blood Test?
You usually get a ferritin blood test because your doctor suspects you have too little or too much iron in your body. That might be because of your symptoms or because other blood tests suggest a problem. You also might get a ferritin test if you're at a risk of low iron levels because you are underweight or pregnant or have heavy periods, a poor diet, or problems with food absorption.
The test can help find or rule out conditions including:
- Iron deficiency anemia. You need iron to make healthy red blood cells, which carry oxygen through your body. When you don't have enough iron, you don't make enough of those cells. That's anemia. The most common cause of iron deficiency anemia in adults is chronic blood loss.
- Hemochromatosis or iron overload. That's when you have too much iron in your body because you absorb too much from the foods you eat. It's a genetic condition.
- Liver disease. Much of the ferritin in your body is stored in your liver. High ferritin can point to a liver problem.
- Adult Still's disease. This rare form of arthritis causes joint pain, fever, and rash. People with this disease have very high ferritin levels.
Symptoms of low ferritin
These are some of thesymptoms of low iron and ferritin that might lead your doctor to order a ferritin test:
- Paler than usual skin
- Shortness of breath
- Rapid heartbeat
- Burning tongue
- Cravings for licorice, chalk, dirt, or clay.
Over the long term, low levels of iron can cause heart failure (when your heart doesn't pump blood to your body as well as it should). It can also cause chest pain, leg pain, and ringing in the ears. Low iron also may be partly to blame for restless leg syndrome.
Symptoms of high ferritin
These are some of the symptoms of high ferritin and iron that might lead your doctor to order a ferritin test:
- Joint pain
- Low interest in sex or trouble with erections
- Belly pain
- Skin that looks gray, metallic, or bronze
- Foggy memory
- Heart problems
- Weight loss
- Body hair loss
High ferritin levels can also be found in people with infections, alcohol abuse disorder, rheumatoid arthritis, overactive thyroid, and some forms of cancer.
How Do I Prepare for a Ferritin Blood Test?
If ferritin is the only test you're having, you can eat and drink as usual. You may need to fast for other blood tests. Always check with your doctor beforehand.
Think about wearing a shirt with short sleeves so the lab technician can get to your arm easily.
How Is a Ferritin Blood Test Performed?
A ferritin test should only take a few minutes. Remember to look away if the sight of blood or a needle makes you dizzy or nauseated.
After cleaning the skin around it, a technician will insert a needle into a vein in your arm. They may wrap an elastic band around the upper part of your arm to make the vein easier to find. Once they've collected the right amount of blood, the technician will remove the band and needle and stop the bleeding with a cotton ball or bandage. They'll label the blood and send it to a lab.
Ferritin Blood Test Risks
Like other routine blood tests, the ferritin test is considered safe. You may feel the following:
- Faint or lightheaded
- A lump or bruise under the skin
- Slight pain where the needle went in
Ferritin Blood Test Results
After your test, you'll get a report showing how much ferritin is in your blood. Different labs use different standards. But the normal ferritin levels, by age, are about:
- 24-336 nanograms per milliliter for adults assigned male at birth
- 24-307 nanograms per milliliter for adults assigned female at birth
- 25-200 nanograms per milliliter for newborns
- 200-600 nanograms per milliliter at 1 month old
- 50-200 nanograms per milliliter at 2-5 months old
- 7-140 nanograms per milliliter for children aged 6 months to 15 years
Low ferritin levels
If you have lower than normal ferritin levels, you may have iron deficiency anemia. Your doctor may order more tests to get a more exact picture of your iron levels. They'll also try to figure out why your levels are low. In adults, the cause is often ongoing blood loss. Heavy periods can be one cause. But bleeding you don't see, often from your stomach or intestines, is another common cause.
Children are more likely to have low levels caused by poor diet. Adults and children sometimes have medical conditions that make it hard for them to absorb iron from food.
High ferritin levels
High ferritin levels can mean you have hemochromatosis. You might also have high iron levels caused by multiple blood transfusions or taking too many iron pills. It's possible to have high levels of ferritin without high levels of iron. That can happen if you have an infection, problems with inflammation, an autoimmune disorder, or some types of cancer.