Ferritin Test

At a Glance

Also known as

Serum ferritin level

Related tests

Serum iron, TIBC&Transferrin

Why get tested?

To learn about your body's current store of iron

When to get tested?

When your doctor suspects that you may have too little or too much iron in your system

Sample required

A blood sample drawn from a vein in your arm

The Test Sample

What is being tested?

Ferritin is a protein inside of cells that stores iron for later use by your body. The small amount of ferritin that is released into blood reflects the total amount of storage iron. Iron is also stored as hemosiderin, a complex of iron, proteins, and other materials. Ferritin and hemosiderin are present primarily in the liver but also in the bone marrow, spleen, and skeletal muscles. In healthy people, most iron is stored as ferritin (an estimated 70% in men and 80% in women) and smaller amounts are stored as hemosiderin.

When iron begins to disappear from your system, iron stores are depleted before iron deficiency develops.

How is the sample collected for testing?

A blood sample is drawn by needle from a vein in your arm.

The Test

How is it used?

The ferritin test is ordered to see how much iron your body has stored for future use. The test is done, usually with an iron test and the TIBC, to learn about iron levels in your blood. Ferritin is the best test for iron deficiency and a very good test for iron overload.

When is it ordered?

If a blood count indicates that your hemoglobin and hematocrit are low, and especially if your red cells are microcytic and hypochromic, iron deficiency is the likely cause of the anemia. Ferritin and other iron tests can be used to confirm the diagnosis.

The test also may be ordered when your doctor suspects that you have iron overload. This may be caused by hemochromatosis or hemosiderosis.

What does the test result mean?

Ferritin levels are low in patients with iron deficiency.

Ferritin levels are high in those with hemochromatosis, a genetic disease in which too much iron is absorbed. However, ferritin may also be increased in patients with inflammation, liver disease, and some types of cancer, and in patients who have had multiple transfusions.

Is there anything else I should know?

Ferritin is normally found mainly inside of cells, with only a small amount in the blood. When there is damage to organs that contain ferritin (especially the liver, spleen, and bone marrow), ferritin levels can become elevated even though the total amount of iron in the body is normal. Ferritin levels may not be particularly helpful in persons with liver disease, chronic infections, cancers, or autoimmune diseases (which are all associated with organ damage).

Common Questions

1. Is iron deficiency the same thing as anemia? What are the symptoms?

   Iron deficiency refers to a decrease in storage iron, while anemia refers to a drop in the amount of hemoglobin in blood. It takes at least several weeks after iron stores are depleted for anemia to develop. Early iron deficiency usually causes no effects at all. If a person is otherwise healthy, symptoms seldom appear before the hemoglobin in your blood drops below a certain level (10 g per deciliter). Some signs that your body is low in iron include tiredness and heart palpitations.

   As your iron continues to be depleted, you may have shortness of breath and dizziness. If the anemia is severe, angina (chest pain), headache, and leg pains may occur. Children may have learning (cognitive) disabilities. Besides the general symptoms of anemia, there are certain symptoms that are characteristic of iron deficiency. These include pica (cravings for specific substances, such as licorice, chalk, dirt, or clay), a burning sensation in the tongue or a smooth tongue, sores at the corners of the mouth, and spoon-shaped finger- and toe-nails.

2. What are signs of iron overload in my system?

   The most common symptom is pain, as iron accumulates in your body, usually in your joints. Other symptoms include fatigue and lack of energy, abdominal pain, loss of sex drive, and heart problems. Some people, however, have no symptoms of this condition.

3. What foods contain the most iron?

   If lab tests show that you are anemic, eating foods that contain iron, such as red meat, can help. Some good choices for an iron-rich diet include: meats, liver, eggs, green leafy vegetables (spinach, collard greens, kale), wheat germ, whole grain breads and cereals, raisins, and molasses. If you have been diagnosed with iron deficiency anemia, or you are pregnant or breast feeding, vitamin pills or tablets are usually needed to provide extra iron. Ask your doctor about the right supplement for you.

4. Who needs iron supplements?

   The people who typically need iron supplements are pregnant women and patients with documented iron deficiency.

5. Does anemia due to iron deficiency happen quickly or does it take a long time?

   Iron deficiency anemia comes on gradually. When your rate of iron loss exceeds the amount of iron you absorb from the gut, iron stores are slowly used up. At this stage, ferritin will be low, but serum iron and TIBC are usually normal and there is no anemia. As iron deficiency worsens, serum iron levels fall, TIBC and transferrin rise, and anemia starts to develop. With prolonged or severe iron deficiency, the red cells become small and pale.

6. Does donating blood affect my iron levels?

   Yes. Every time you donate a pint of blood, your body loses about 250 mg of iron. The level of serum ferritin, which is a reflection of the total amount of storage iron, drops with each donation. The more blood you donate, the lower the ferritin becomes. Other tests, such as serum iron and TIBC, are not as affected by blood donation.