Ferritin is the protein that stores iron inside of the cells in your body. The test measures the ferritin that is released into circulation and reflects the amount of stored iron.
Iron is essential to produce red blood cells. Iron is not produced by the body, so must be absorbed from either food sources or supplements. Absorbed iron is incorporated into haemoglobin of the red blood cells. Excess iron is stored as ferritin or hemosiderin in body tissue like liver, spleen, bone marrow and muscles. When iron is insufficient to meet the body's requirements, the iron level in the blood will drop and the iron stores will become depleted, thus decreasing the ferritin level.
The causes for becoming iron insufficient include:
Complcations can arise from longstanding iron shortages, including a decreased amount of haemoglobin called iron deficiency anaemia. Symptoms of iron shortage only develops later when anaemia sets in and include fatigue, general weakness, dizziness, headaches and a pale skin.
Iron storage can also increase in the event that more iron is absorbed than your body requires, and over time can cause excess deposition in organs as is seen in the genetic condition called haemochromatosis. Iron overload can occur in patients that receive many blood transfusions or intravenous iron supplementation.
The ferritin test assesses the iron stores in the body. Accompanying tests include an actual serum iron level and total iron-binding capacity.
A ferritin test is usually ordered when a person develops signs and symptoms of iron-deficiency anaemia, including:
The test is also ordered when there the haemoglobin level is low and together with other iron tests used to establish a diagnosis of iron deficiency anaemia.