Iron tests are a group of blood tests that are done to evaluate the iron level in blood serum, the body's capacity to absorb iron, and the amount of iron actually stored in the body. Iron is an essential trace element; it is necessary for the formation of red blood cells and certain enzymes. At the other extreme, high levels of iron can be poisonous.
There are four different types of tests that measure the body's iron levels and storage. They are called iron level tests, total iron-binding capacity (TIBC) tests, ferritin tests, and transferrin tests. These tests are given for several reasons:
to help in the differential diagnosis of different types of anemia
to assess the severity of anemia and monitor the treatment of patients with chronic anemia
to evaluate protein depletion and other forms of malnutrition
A serum iron test can be used without the others to evaluate cases of iron poisoning.
Patients should not have their blood tested for iron within four days of a blood transfusion or tests and treatments that use radioactive materials. Recent high stress levels or sleep deprivation are additional reasons for postponing iron tests.
Blood samples for iron tests should be taken early in the morning because serum iron levels vary during the day. This precaution is especially important in evaluating the results of iron replacement therapy.
Rebecca J. Frey PhD, The Gale Group Inc., Gale, Detroit,