Secondary iron overload occurs when iron accumulates in the body because people take too many iron supplements, receive a large number of blood transfusions, or have a disorder in which they cannot form red blood cells efficiently.
People often feel weak and tired.
Diagnosis is with blood tests to measure iron level.
Treatment is usually with drugs that bind and remove iron from the body (chelation).
Severe complications are less likely than in people who have hemochromatosis, a genetic disorder that causes iron overload. (See also Overview of Iron Overload.) However, some people develop complications involving the heart, the liver, and endocrine organs.
Causes of Secondary Iron Overload
Secondary iron overload typically occurs in people who have disorders that impair red blood cell production such as
Inherited disorders of hemoglobin structure or function (for example, sickle cell disease, thalassemia, or sideroblastic anemias)
Disorders that cause abnormal breakdown of red blood cells (hemolytic anemias that are present from birth such as hereditary spherocytosis or pyruvate kinase deficiency—see table More About Some Causes of Anemia)
Disorders caused by poorly formed red blood cells (myelodysplasia)
In such disorders, the body sometimes increases the amount of iron it absorbs. However, the body cannot always use all of the iron because of the difficulty of producing new red blood cells. In such cases, iron overload can occur.
Iron also can accumulate in the body when people take in too much iron from
Iron therapy given in excessive amounts or for too long
Repeated blood transfusions
Men and postmenopausal women do not usually need to take iron supplements. If they do take supplements, they may have excess iron in the body, although usually not enough to be dangerous.
Symptoms of Secondary Iron Overload
People with mild iron overload usually have no symptoms. Others typically feel weak and fatigued. Severe iron overload causes the same symptoms as in hemochromatosis:
Bronze-colored skin
Heart failure (occasionally)
Joint pains
Increased risk of liver cancer
An underactive thyroid gland (hypothyroidism)
Diagnosis of Secondary Iron Overload
Blood tests
Secondary iron overload is diagnosed by tests that measure blood levels of
Iron
Ferritin, a protein that stores iron
Transferrin, the protein that carries iron in blood when iron is not inside red blood cells
Treatment of Secondary Iron Overload
Removal of blood or chelation
The goal of treatment is to reduce the body's iron content. For some people, treatment is to remove blood (phlebotomy). However, many people with secondary iron overload also have anemia. Because phlebotomy worsens anemia, these people are given iron chelation therapy.
Iron chelation drugs given by mouth are very effective in lowering the iron level in the body. Side effects of oral iron chelation include abdominal pain, diarrhea, and rash. The treatment sometimes causes liver and kidney damage, so blood tests are done periodically to monitor the function of these organs.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Iron Disorders Institute: provides information about disorders that cause iron imbalance, including testing and tips for living with these disorders
