hemosiderin: meaning, definition, pronunciation and examples

Ferritin is a soluble, spherical protein complex that stores iron in a non-toxic, readily available form. Hemosiderin is an insoluble, granular degradation product of ferritin and other proteins, representing a long-term, less accessible storage form of iron.

Hemosiderin itself is not inherently dangerous; it is a normal byproduct of hemoglobin breakdown. However, its excessive accumulation in tissues (hemosiderosis or hemochromatosis) indicates iron overload, which can damage organs like the liver, heart, and pancreas.

It is found in conditions involving chronic bleeding or hemolysis (e.g., hereditary hemochromatosis, thalassemia, chronic venous stasis ulcers, pulmonary hemosiderosis, and after repeated blood transfusions).

When present in very large amounts, it can impart a rusty brown discoloration to tissues (e.g., skin in hemochromatosis – 'bronze diabetes'; or the lungs in idiopathic pulmonary hemosiderosis). However, definitive identification requires microscopic examination with special stains like Prussian blue.

An iron-storage protein complex found within cells, particularly in tissues like the liver, spleen, and bone marrow, which appears as yellow-brown granules.

Hemosiderin is usually formal, technical, medical in register.

Hemosiderin: in British English it is pronounced /ˌhiːmə(ʊ)ˈsɪdərɪn/, and in American English it is pronounced /ˌhiːmoʊˈsɪdərɪn/. Tap the audio buttons above to hear it.