Ferritin is a protein found inside cells that stores iron so your body can use it later. A ferritin test indirectly measures the amount of iron in your blood.
The amount of ferritin in your blood (serum ferritin level) is directly related to the amount of iron stored in your body.
Serum ferritin level
A blood sample is needed. For information on how this is done, see: Venipuncture
Your doctor may tell you to stop taking any drugs that may affect the test results.
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
This test measures the amount of iron in the body. Iron is important for red blood cell production. Your doctor may order this test if you have signs or symptoms of anemia.
Note: ng/ml = nanograms per milliliter
The lower the ferritin level, even within the "normal" range, the more likely it is that the patient does not have enough iron.
The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
Any inflammatory disorder can raise the ferritin level.
Higher-than-normal ferritin levels may be due to:
Lower-than-normal levels may be due to:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
Bunn HF. Approach to the anemias. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 161.
Hoffman R, Benz Jr. EJ, Shattil SJ, et al., eds. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, Pa: Churchill Livingston; 2005:482.