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Serum iron test

  • Definition
    • A serum iron test measures how much iron is in your blood.

  • Alternative Names
    • Fe+2; Ferric ion; Fe++; Ferrous ion; Iron - serum; Anemia - serum iron; Hemochromatosis - serum iron

  • How the Test is Performed
    • A blood sample is needed.

      Iron levels are highest in the morning. Your health care provider will likely have you do this test in the morning.

  • How to Prepare for the Test
    • Certain medicines may affect the results of this test. Your provider will tell you if you need to stop taking any medicines. DO NOT stop any medicine before talking to your provider.

      Medicines that can affect the test result include:

      • Antibiotics
      • Birth control pills and estrogens
      • Blood pressure drugs
      • Cholesterol drugs
      • Deferoxamine (removes excess iron from the body)
      • Gout drugs
      • Testosterone
  • How the Test will Feel
    • When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

  • Why the Test is Performed
    • Your provider may recommend this test if you have:

      • Signs of low iron (iron deficiency)
      • Signs of too much iron
      • Anemia caused by a chronic disease
  • Normal Results
    • Normal value range is:

      • Iron: 60 to 170 micrograms per deciliter (mcg/dL) or 10.74 to 30.43 micromoles per liter (micromol/L)
      • Total iron binding capacity (TIBC): 240 to 450 mcg/dL or 42.96 to 80.55 micromol/L
      • Transferrin saturation: 20% to 50% (transferrin moves iron through the blood)

      The numbers 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 provider about the meaning of your specific test results.

  • What Abnormal Results Mean
    • Higher-than-normal iron level may mean:

      • Too much iron in the body (hemochromatosis)
      • Anemia due to red blood cells being destroyed too quickly (hemolytic anemia)
      • Liver tissue death
      • Inflammation of the liver (hepatitis)
      • Iron poisoning
      • Many blood transfusions

      Lower-than-normal levels may mean:

      • Long-term digestive tract bleeding
      • Heavy menstrual bleeding
      • Intestinal conditions that cause poor absorption of iron
      • Not enough iron in the diet
      • Pregnancy
  • Risks
    • There is very little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood 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 lightheaded
      • Hematoma (blood buildup under the skin)
      • Infection (a slight risk any time the skin is broken)
  • References
    • Brittenham GM. Disorders of iron homeostasis: iron deficiency and overload. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 34.

      Bunn HF. Approach to the anemias. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 158.

      Little JA, Benz EJ, Gardner LB. Anemia of chronic diseases. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 35.