Typical adults lose about 1 mg iron (Fe) per day in shed epidermal and gastrointestinal cells; menstruating females lose on average an additional 0.5 to 1 mg/day from menses. This iron loss is balanced by absorption of a portion of the 10 to 20 mg of iron in a typical US diet. Iron absorption is regulated based on the body's iron stores and is usually in balance with the body's needs. However, because there is no physiologic mechanism to remove iron from the body, iron absorbed in excess of bodily needs (or acquired through repeated transfusion) is deposited in tissues.
Hemosiderosis Hemosiderosis Hemosiderosis is focal deposition of iron that does not typically cause tissue damage. (See also Overview of Iron Overload.) Focal hemosiderosis can result from hemorrhage within an organ. Iron... read more is focal deposition of iron that typically does not cause tissue damage.
Hemochromatosis (iron overload) is a typically systemic process in which iron deposition can cause tissue damage.
Iron overload may result from hereditary hemochromatosis Hereditary Hemochromatosis Hereditary hemochromatosis is a genetic disorder characterized by excessive iron (Fe) accumulation that results in tissue damage. Manifestations can include systemic symptoms, liver disorders... read more 
(a genetic disorder of iron metabolism) or from secondary hemochromatosis Secondary Iron Overload Secondary iron overload results from excess absorption of iron, repeated blood transfusions, or excess oral intake, typically in patients with disorders of erythropoiesis. Consequences can include... read more , an acquired form of the disease that is due to excess oral intake or absorption of iron or to repeated blood transfusions (1, 2 General references Typical adults lose about 1 mg iron (Fe) per day in shed epidermal and gastrointestinal cells; menstruating females lose on average an additional 0.5 to 1 mg/day from menses. This iron loss... read more ). Morbidity is mainly due to iron accumulation in the endocrine organs (especially the pancreas, gonads, and pituitary), liver, and heart.
African iron overload occurs most often in sub-Saharan Africa among people who consume an iron-rich fermented drink. A genetic component is thought to contribute to the pathogenesis of African iron overload, but no gene has yet been identified.
(See also Iron Poisoning Iron Poisoning Iron poisoning is a leading cause of poisoning deaths in children. Symptoms begin with acute gastroenteritis, followed by a quiescent period, then shock and liver failure. Diagnosis is by measuring... read more and Idiopathic Pulmonary Hemosiderosis Idiopathic Pulmonary Hemosiderosis Idiopathic pulmonary hemosiderosis is a rare disease that causes recurrent diffuse alveolar hemorrhage with no detectable underlying disorder; it occurs mainly in children < 10 years. In... read more .)
General references
1. Bacon BR, Adams PC, Kowdley KV, et al: Diagnosis and management of hemochromatosis: 2011 Practice Guideline by the AASLD. Hepatology 54 (1): 328–343, 2011.
2. Fleming RE, Ponka P: Iron overload in human disease. New Engl J Med 366:348–359, 2012.
