Ferritin is a protein found inside cells that stores iron so your body can use it later. A ferritin test 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.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore blood flow. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

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.

Male: 12-300 ng/mL

Female: 12-150 ng/mL

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.

Any inflammatory disorder can raise the ferritin level.

Higher-than-normal ferritin levels may be due to:

• Alcoholic liver disease
• Hemochromatosis
• Hemolytic anemia
• Hodgkin's lymphoma
• Megaloblastic anemia

• Long-term digestive tract bleeding
• Heavy menstrual bleeding
• Iron deficiency anemia

Additional conditions under which the test may be performed:

• Anemia of chronic disease

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)
• Multiple punctures to locate veins

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.

McPherson RA and Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: WB Saunders; 2007:78.

Hoffman R, Benz Jr. EJ, Shattil SJ, et al., eds. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, Pa: Churchill Livingston; 2005:482.