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Friday 13 January 2006

Hemosiderin or haemosiderin is an abnormal microscopic pigment found in the human body.

Hemosiderin is composed of iron oxide and can accumulate in different organs in various diseases.


Several diseases result in deposition of Iron(III) oxide-hydroxide in tissues in an insoluble form. These deposits of iron are called hemosiderin.

Although these deposits (hemosiderosis) often cause no symptoms, they can lead to organ damage (hemochromatosis).

Hemosiderin often forms after bleeding (hemorrhage). When blood leaves a ruptured blood vessel, the cell dies and the hemoglobin of the red blood cells is released into the extracellular space. White blood cells called macrophages engulf (phagocytose) the hemoglobin to degrade it, producing hemosiderin and porphyrin.

Hemosiderin may deposit in diseases associated with iron overload. These diseases are typically diseases in which chronic blood loss requires frequent blood transfusions, such as sickle cell anemia and thalassemia.

See also

- iron
- iron deposits
- iron metabolism
- hemochromatosis
- hemosiderosis