Composed of iron and protein, Ferritin is a storehouse for iron in the body. Measurement provides an accurate picture of how much iron you have available in reserve. It is used to evaluate anemia and for diagnosing iron deficiency. The ferritin test is ordered to see how much iron your body has stored for future use. The test is done, usually with an iron test and the TIBC to learn about your iron levels in your blood.
If a blood count indicates that your Hemoglobin and Hematocrit are low, especially if your red cells are smaller and paler than normal (microcytic and hypochromic in medical terms), iron deficiency is a likely cause for the anemia.. Ferritin and other iron tests can be used to confirm the diagnosis.
Ferritin levels are low in chronic iron deficiency and or if your body proteins are severely depleted, as in some cases of malnutrition.
On the other hand this test also may be ordered when one suspects you may have too much iron, in cases of iron overload, iron poisoning, situation called hemosiderosis (too much iron accumulating from disease or ingestion), and hemochromatosis.
Ferritin is normally found mainly inside of cells, with only a small amount in the blood. When there is damage to organs that contain ferritin (especially the liver, spleen, and bone marrow), ferritin levels can become elevated even though the total amount of iron in the body is normal. Ferritin levels may not be particularly helpful in persons with liver disease, chronic infections, cancers, or autoimmune diseases (which are all associated with organ damage).