Ferritin is a blood protein that stores iron. A ferritin blood test can indicate if iron levels are high or low. Low levels can indicate anemia.

Low ferritin levels may indicate an iron deficiency. While not every case of anemia is due to iron deficiency, iron deficiency anemia is the most common type.

High ferritin levels can occur with an iron overload disorder such as hemochromatosis, which causes the body to store too much iron. However, several conditions may contribute to elevated ferritin levels.

Treatment options will depend on why the ferritin levels are too high or too low. Treating the underlying condition may improve the ferritin levels.

This article looks at ferritin blood tests, what the different ferritin blood levels may mean, and how to increase or decrease ferritin levels.

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The ferritin blood test measures how much iron is stored in a person’s body.

Ferritin is a protein that stores iron inside cells. Iron plays a critical role in several metabolic processes including carrying oxygen throughout the body and moving electrons within cells.

When a person shows signs of having too much or too little iron, a ferritin blood test can help diagnose or rule out certain medical conditions.

These conditions include:

Additionally, doctors may order ferritin blood tests to monitor chronic health conditions, such as autoimmune diseases, kidney disease, and cancer.

Symptoms of low ferritin in blood

Someone with low ferritin levels, or low iron levels, may experience:

Iron deficiency anemia can cause such symptoms. However, this is true for many other health conditions. Anyone with these symptoms should see a doctor for evaluation.

People may measure ferritin levels in micrograms per liter (mcg/l) of blood. Test results may come back as normal, low, or high.

The following sections discuss what these results mean.

Normal ferritin levels

“Normal” levels can vary slightly from one lab to another, and a person should confirm what “normal” means with their doctor.

According to the United Kingdom’s National Health Service (NHS), normal ferritin levels are between 41 to 400 mcg/l and borderline levels are between 16 to 40 mcg/l.

Low ferritin levels

Low ferritin levels suggest an iron deficiency. The NHS suggests that low levels are less than 15 mcg/l.

The body needs iron to make hemoglobin, a protein in red blood cells that transfers oxygen from the lungs around the body.

Iron is also necessary for:

  • growth and development
  • metabolism
  • the production of hormones

An iron deficiency can occur with or without anemia. However, it is the most common cause of anemia.

Iron-deficiency anemia can cause the following:

However, mild anemia may not produce any symptoms.

High ferritin levels

High ferritin levels can indicate a person has too much iron in their blood. The NHS suggests that high levels are greater than 400 mcg/l.

A person with very high iron levels may experience:

Several health conditions may lead to increased ferritin and iron levels, including:

Other factors that can lead to high iron levels are blood transfusions and dietary factors, including the use of supplements.

A person with high ferritin levels will need more tests to identify the underlying cause and help doctors determine the best course of treatment.

If a person has low ferritin or iron levels, their doctor will need to evaluate how severe the deficiency is and identify the underlying cause.

If low iron levels result from bleeding, the doctor will address this problem.

They may also advise the individual on boosting their iron levels, for example, through dietary choices.

Some foods that provide iron include:

  • lean red meat
  • oysters
  • lentils, beans, and tofu
  • raisins
  • eggs
  • fortified breakfast cereals
  • dark leafy greens, including spinach, kale, and broccoli

Some foods and drinks can affect iron absorption.

For example, supplements and foods rich in vitamin C may help increase iron absorption. However, other compounds, like polyphenols, can reduce iron absorption.

A doctor may recommend iron supplements to increase ferritin levels.

People can take oral iron supplements at home. However, they should only use them under the supervision of a doctor.

In severe cases of anemia, they may require treatment with intravenous iron.

Typically, a person’s doctor will order follow-up blood tests. If levels do not return to the accepted range, the doctor may recommend more testing to determine the cause of the deficiency or suggest a different treatment plan.

Read about which foods can help boost iron levels.

A person with high ferritin levels may have high iron levels. Treatment for high iron levels depends on the underlying cause.

Treatment for iron overload disorders, such as primary hemochromatosis, is usually with phlebotomy. This is a regular treatment to remove iron-rich blood from the body.

The amount of blood the doctor removes, and how frequently they remove it, will depend on factors such as a person’s age, health, and ferritin levels.

Sometimes, doctors use iron chelation therapy. This involves an oral or injected medication that removes excess iron from the body. Typically, iron chelation therapy is not the first option for hemochromatosis. However, it may be suitable for some people.

People with other conditions that cause high ferritin levels may require additional or different treatments.

Generally, a ferritin blood test is a quick, simple procedure.

As with other blood tests, a healthcare professional will:

  • Wrap a band around the person’s arm to make their veins more visible.
  • Clean an area of skin with an antiseptic swap.
  • Insert a small needle into the vein and collect a blood sample into a vial.

After collecting the blood sample, the healthcare professional will apply a dressing and remove the band.

Ferritin tests typically do not usually cause major side effects. The person may feel a stinging sensation when the needle goes in or out, and there may be some bruising and bleeding.

The person should contact their doctor if they experience:

A person’s doctor will advise them on how to prepare for a ferritin blood test.

A person may need to fast before the test for a specific period of time leading up to the test. This may give the doctor the most accurate measure of iron stores.

Some at-home iron tests can check iron levels. However, there are pros and cons.

The most obvious benefit to at-home iron tests is convenience. A person does not have to make an appointment or get a referral from their doctor. Many companies use accredited laboratories to process the results, and some provide results online or via an app within a couple of days.

Additionally, some companies accept payment through health savings accounts (HSAs) and flexible spending accounts (FSAs).

On the other hand, not all at-home iron tests are actually at home. Some companies require people to visit an affiliate laboratory location for the procedure.

Plus, some at-home iron tests can be expensive, particularly if the company does not accept HSAs or FSAs. If the person’s insurance provider does not cover the test–the out-of-pocket cost might hurt.

A person should discuss with a doctor:

  • if they need a test
  • where to have the test
  • what the follow-up should be

There is a lack of research confirming the safety and accuracy of at-home ferritin tests.

A 2021 review concluded that blood draw ferritin tests “may be reasonably accurate” in diagnosing low iron levels. However, their accuracy for diagnosing iron overload is unclear, due to a lack of research. The review did not include at-home tests.

A ferritin blood test measures ferritin levels in a person’s body. Ferritin stores iron, so this test gives an indication of the individual’s iron levels.

The test is typically fairly quick and does not require any special preparations, although a doctor may ask the person to fast.

High or low results may indicate an underlying issue, such as iron deficiency anemia, hemochromatosis, or some types of cancer.

Additional testing may be necessary to confirm a diagnosis and help formulate a treatment plan.