How is it used?When is it ordered?What does the test result mean?Is there anything else I should know?
Iron and
total iron-binding capacity (TIBC) are measured together to identify how much iron is being carried in the blood. In persons with
anemia, these tests can help to determine whether it is due to iron deficiency or another cause, such as chronic illness.
These same two tests are also used to screen for hereditary hemochromatosis. The College of American Pathologists recommends screening for hemochromatosis in all people over age 20 because of the low cost of diagnosis and treatment if caught early. Other organizations have not yet recommended screening because it is not yet possible to tell which persons who have the abnormal genes will never develop symptoms and which will develop organ damage. A number of studies are currently underway to develop a strategy to determine when and how to screen people.
Iron tests are not ordered routinely. If
hemoglobin and
hematocrit are abnormally low, however, iron tests can be very useful in determining the cause of
anemia. Iron tests can also be used when iron deficiency is being treated to tell if the iron is being absorbed properly and to detect when enough iron has been taken. The test also may be ordered when your doctor suspects you may have too much iron. If you have symptoms that could be due to
hemochromatosis, iron tests represent the best way to determine whether this could be the diagnosis. In a child who has ingested iron tablets, iron levels are the only way to determine the severity of poisoning.
What does the test result mean?NOTE: A standard reference range is not available for this test. Because
reference values are
dependent on many factors, including patient age, gender, sample population, and test
method, numeric test results have different meanings in different labs. Your lab report
should include the specific reference range for your test. Lab Tests Online strongly
recommends that you discuss your test results with your doctor. For more information on
reference ranges, please read Reference Ranges
and What They Mean.
A low iron with a high
transferrin or
TIBC is usually due to iron deficiency. In chronic diseases, both iron and transferrin or TIBC are typically low. Low iron can cause
anemia and is usually due to long-term or heavy bleeding,
pregnancy, rapid growth (in children), or an iron-poor poor diet.
High levels of serum iron can occur as the result of multiple blood transfusions, iron injections into muscle, lead poisoning, liver disease, or kidney disease. It can also be due to the genetic disease hemochromatosis.
Is there anything else I should know?
Samples for iron should be taken in the morning, before you have had any food to eat. You should not take any iron pills or tablets for 24 hours before the test. Iron is absorbed rapidly from food or pills and can make your iron levels falsely high.
