Ferritin Test
Overview
Ferritin is a type of protein that stores iron in the body. It plays a major role in iron metabolism by keeping iron available when needed and preventing too much iron from building up. A ferritin blood test measures ferritin levels and often serves as a screening tool to check the bodyโs iron stores.
Low ferritin means iron deficiency, which can lead to anemia. High ferritin can signal inflammation, such as from liver disease or arthritis, or other issues like too much iron storage or certain cancers. Ferritin also acts as an acute phase reactant, which means its levels can rise when the body is fighting illness or inflammation.
Reasons for Testing
A ferritin blood test helps doctors check iron storage in the body. Doctors use it to find or monitor conditions like iron deficiency anemia, hemochromatosis, certain liver problems, and rare types of inflammatory arthritis such as adult Still disease.
| Condition | Purpose of Test |
|---|---|
| Iron deficiency anemia | Diagnose low iron stores. |
| Hemochromatosis | Check for excess iron. |
| Liver disease | Detect related changes. |
| Adult Still disease | Identify inflammation. |
Health professionals use the results to guide treatment and compare possible causes of symptoms when making a differential diagnosis.
Getting Ready for the Test
To prepare for a ferritin blood test, most people can eat and drink as usual if the test is only for ferritin. If other tests are being done with it, fasting may be required for about 12 hours. Follow the advice given by your health care team. Iron therapy does not usually need a change unless your provider tells you otherwise.
What to Expect During the Procedure
A health care professional uses a needle to draw a small amount of blood from a vein in the arm. The laboratory receives the collected blood sample for testing. Most people can resume normal activities right after the blood test.
Findings from Ferritin Test Results
When Ferritin Levels Are Below the Normal Range
Low ferritin levels usually signal that the body’s iron stores are low. This can mean iron deficiency, which may lead to iron deficiency anemia. When the body does not have enough iron, it cannot make enough hemoglobin.
This affects red blood cell production and reduces the bloodโs ability to carry oxygen. Common reasons for low ferritin include:
- Blood loss (for example, from heavy periods or gastrointestinal bleeding).
- Poor dietary iron intake.
- Issues with iron absorption in the digestive tract.
Doctors may use other tests, such as transferrin saturation, hemoglobin, or total iron binding capacity, to better assess iron status. Patients with low ferritin may also show changes in mean corpuscular volume and red cell distribution width.
Table: Typical Ferritin Levels
| Group | Typical Range (mcg/L) |
|---|---|
| Men | 24โ336 |
| Women | 11โ307 |
When Ferritin Levels Are Higher Than Normal
Elevated ferritin often points to too much iron in the body, a condition known as iron overload. Genetic disorders like hemochromatosis or repeated blood transfusions can cause this.
High ferritin can also occur in liver diseases, heart failure, and some cancers such as leukemia or Hodgkin’s lymphoma. Other possible causes include:
- Chronic inflammatory diseases (for example, rheumatoid arthritis)
- Hyperthyroidism
- Heavy alcohol use
- Too much iron from supplements
A person with higher ferritin may not always have symptoms. Doctors often order extra tests โ like checking liver function, bone marrow, or more detailed iron studies (iron levels, transferrin saturation) โ to find out why ferritin is elevated.
