(See also Overview of Iron Overload.)
Hemosiderosis is a term used for excessive accumulation of iron deposits called hemosiderin in the tissues.
The lungs and kidneys are often sites of hemosiderosis. Hemosiderosis can result from
Direct bleeding into the tissues that is followed by breakdown of red blood cells and release of iron to the tissues
Destruction of red blood cells within the blood vessels, leading to release of iron into the blood followed by accumulation of iron inside the kidneys as the kidneys filter waste from the blood.
Organs may be damaged by the iron deposits. The extent of the damage depends on how much iron is deposited in the organs. Some people have no damage at all, whereas others have some damage. Hemosiderosis caused by bleeding and red blood cell breakdown does not usually require treatment.
If there is bleeding within an organ, such as in the lungs of people who have certain types of lung disease, iron from the blood cells often remains in that organ. Depending on the amount of iron that remains in the lungs people may have no problems or varying degrees of lung damage.
If people have a disorder that causes excessive breakdown of red blood cells within the blood vessels (for example, hemolytic anemia), iron released from the red blood cells can accumulate within the kidneys (renal hemosiderosis). Most cases of renal hemosiderosis do not cause kidney damage.
Hemosiderosis can also occur due to excessive iron absorption, but in that case, doctors call the condition hemochromatosis. Hemochromatosis more often requires treatment.