Ferritin to Measure Iron: What Testing Shows
Low ferritin may indicate anemia, while high ferritin may indicate inflammation
Medically reviewed by Steffini Stalos, DO
Ferritin is a protein that binds to iron, an important mineral needed for red blood cells to circulate oxygen throughout the body. Your ferritin blood concentration can be measured, and the result reflects your iron levels. High or low ferritin levels can occur with a variety of medical conditions.
Your ferritin concentration can help diagnose various disorders when used in conjunction with other screening tools.
This article describes the role of ferritin and what you should expect if your ferritin levels are not normal.
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Ferritin Protein and Iron Storage
Iron, a mineral, is an essential component of hemoglobin in red blood cells and myoglobin in muscles. Iron binds to ferritin in other cells and in the blood circulation.
Ferritin is a protein that stores iron so it can be used by cells throughout the body, including red blood cells, the liver, and the bone marrow.
Ferritin plays a role in regulating the body’s use of iron. This protein may also play a role in the health and survival of various types of cells throughout the body, such as in the nervous system. Researchers are learning more about ferritin and how this protein affects health and disease.
The Difference Between Ferritin and Iron
The following are differences between iron and ferritin:
Iron is a mineral, and ferritin is a protein.
You get iron directly from the food you eat, and your body makes ferritin by using building blocks from the food you eat.
Iron in red blood cells carries oxygen, which is required for energy in cells throughout the body.
Ferritin binds to iron in the body’s cells and blood circulation.
Measuring Ferritin: What’s Normal?
The concentration of ferritin in your bloodstream can be measured with a blood test. Typically, ferritin concentration is used to assess iron levels in the body.
Having a high iron level or a low iron level is often a sign of disease. When iron is too high or too low, it can cause symptoms and harmful effects in the body. Additionally, sometimes high or low ferritin levels may be associated with medical conditions that are not directly correlated with iron levels.
Normal ferritin levels range between 12 and 150 nanograms per milliliter (ng/mL) for females and from 15 to 200 ng/mL for males. These are equivalent units to micrograms per liter (mcg/L). Health organizations may use either one or the other units.
However, medical conditions can cause higher or lower ferritin levels. For instance, people with an infection, inflammatory reaction, or an underlying medical illness would be expected to have a high ferritin level until the illness resolves.
So, high ferritin levels might not be an indication of iron overload in these circumstances. The ferritin level threshold for consideration of iron deficiency is higher under these circumstances, too. The following chart is based on guidelines from the World Health Organization (WHO).
| Indication of iron deficiency if otherwise healthy | Indication of iron deficiency during an infectious or inflammatory illness | Indication of iron overload if otherwise healthy | Indication of iron overload with an underlying health condition |
Children younger than age 5 | Serum ferritin less than 12 mcg/L | Less than 30 mcg/L |
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Females older than age 5 | Serum ferritin less than 15 mcg/L | Less than 70 mcg/L | Higher than 150 mcg/L | Higher than 500 mcg/L |
Males older than age 5 | Serum ferritin less than 15 mcg/L | Less than 70 mcg/L | Higher than 200 mcg/L | Higher than 500 mcg/L |
In pregnant people | Serum ferritin less than 15 mcg/L |
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|
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Low Ferritin Levels
Generally, low ferritin levels are a reflection of low iron. An iron deficiency can develop due to a number of causes, such as acute or chronic bleeding, blood disorders, low dietary iron or low iron absorption, and chronic medical illness, such as cancer.
Iron deficiency is a common cause of anemia (low levels of healthy red blood cells), but there are also other causes of anemia besides iron deficiency anemia.
High Ferritin Levels
High ferritin levels can be an indication of iron overload, or they may occur even when iron levels are normal or low.
Hemochromatosis is a hereditary condition that can cause iron overload. Repeated blood transfusions can also cause iron overload.
Sometimes, medical illnesses can cause high ferritin levels without iron overload. Hypertension (chronic high blood pressure), cancer, diabetes, and liver disease may raise ferritin levels, but these conditions do not always have this effect.
Low Iron/High Ferritin and High Ferritin/Low Iron
Usually, iron and ferritin levels are both elevated or both deficient—but there are some exceptions.
Low ferritin can be a consequence of:
Iron deficiency
Early-stage iron deficiency with normal serum iron level
It is uncommon to have low ferritin if your iron level is high or normal.
Elevated ferritin can be a consequence of:
Iron overload
Infection
Inflammation
Illness
You can have high serum ferritin with iron deficiency if you have an infection, inflammation, or illness.
How to Tell If Ferritin Levels Are Not Normal
The symptoms of abnormal ferritin levels are nonspecific, which means that they are not specific to a single medical condition. With high or low ferritin levels, you may experience fatigue, dizziness, difficulty sleeping, and difficulty concentrating.
Low Ferritin Symptoms
In addition to feeling tired, dizzy, and having trouble sleeping and concentrating, you may experience symptoms of low iron if your ferritin is low.
Symptoms of low iron may include:
Pale skin
Frequently feeling colder than usual
Rapid heart rate
Bleeding (such as blood in the stool) if blood loss is the cause
If your ferritin and iron levels are low due to a medical illness, you will also develop symptoms of that illness.
Related: Symptoms of Iron Deficiency Anemia
High Ferritin Symptoms
Few symptoms are directly caused by high ferritin levels, but you can have symptoms associated with the conditions that cause them. For example, if you have high ferritin due to inflammation or cancer, you may have symptoms such as pain, fever, swelling, or other symptoms caused by the underlying condition.
High ferritin due to iron overload can cause symptoms of iron overload.
Iron overload symptoms include:
Joint pain
Abdominal pain
General weakness
A Blood Test Detects Ferritin
Ferritin and iron levels are measured with a blood test. Underlying conditions can usually be diagnosed with a variety of tests. Risk factors, symptoms, and physical examination would guide the specific testing.
How to Tell If You Have an Abnormal Ferritin Level
You can't specifically "feel" symptoms of abnormal ferritin. But if you have had low or high ferritin in the past, it's important to ask your healthcare provider for guidance about which symptoms to watch out for—they could be indications that your condition is getting worse.
Treatment to Balance Ferritin
In general, ferritin levels are not directly treated, but you may need treatment for abnormal iron levels or for the underlying disease that’s causing abnormal ferritin levels.
Treatment for iron deficiency can include iron supplementation or blood transfusion. Interventions for high iron levels may include a therapeutic phlebotomy, which is removal of blood through the vein to lower overall iron levels in the body.
Therapies for low ferritin level or for a high ferritin level that is not caused by iron deficiency or iron overload involve management of the underlying risk factors in order to avoid recurrent symptoms and complications.
When to Check Iron Levels
It’s difficult to know whether you have an abnormal ferritin level based on symptoms. However, if you have any of the symptoms associated with abnormal ferritin levels—fatigue, dizziness, joint pain, or feeling cold—it’s important that you see a healthcare provider.
While these symptoms are nonspecific, your evaluation and testing will be guided by your medical history, associated symptoms, and any other underlying conditions that you have.
If your ferritin level is abnormal, you will be treated and provided with guidelines regarding follow-up testing. If your symptoms do not improve as anticipated, make sure to call your healthcare provider to discuss next steps.
Summary
Ferritin is an important protein that binds to iron. A simple blood test can measure ferritin concentration in the blood. Abnormal concentrations of ferritin could reflect iron deficiency or overload and may also be associated with other medical conditions.
Looking at your ferritin level in isolation is not enough to identify or diagnose any medical problem. This test is used along with other tests and with consideration to your symptoms and medical history.
A Note on Sex and Gender Terminology
Verywell Health acknowledges that sex and gender are related concepts, but they are not the same. To reflect our sources accurately, this article uses terms like “female,” “male,” “woman,” and “man” as the sources use them.
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