Ferritin

Answer 1

Definition

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.

Alternative Names

Serum ferritin level

How the test is performed

Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

How to prepare for the test

Your doctor may tell you to stop taking any drugs that may affect the test results.

How the test will feel

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.

Why the test is performed

This test measures the amount of iron in the body. Iron is important for red blood cell production.

Additional conditions under which the test may be performed:

• Anemia of chronic disease

Normal Values

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.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Any inflammatory disorder can raise the ferritin level.

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

• Alcoholic liver disease
• Frequent transfusion of packed red blood cells
• Hemochromatosis

Lower-than-normal levels may be due to:

• Heavy menstrual bleeding
• Intestinal conditions that cause poor absorption of iron
• Iron deficiency anemia
• Long-term digestive tract bleeding

What the risks are

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:

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

References

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.

Answer 2

Definition

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.

Alternative Names

Serum ferritin level

How the test is performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to prepare for the test

Your doctor may tell you to stop taking any drugs that may affect the test results.

How the test will feel

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.

Why the test is performed

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.

Normal Values

• 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.

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.

What abnormal results mean

Any inflammatory disorder can raise the ferritin level.

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

• Alcoholic liver disease
• Frequent transfusion of packed red blood cells
• Hemochromatosis

Lower-than-normal levels may be due to:

• Heavy menstrual bleeding
• Intestinal conditions that cause poor absorption of iron
• Iron deficiency anemia
• Long-term digestive tract bleeding

What the risks are

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:

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

References

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.

Reviewed By

Review Date: 02/08/2012

Todd Gersten, MD, Hematology/Oncology, Palm Beach Cancer Institute, West Palm Beach, FL. Review provided by VeriMed Healthcare Network; Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.