Spherocytosis, in most cases, is an inherited disease that destroys red blood cells. This destruction of the red blood cells causes anemia.
The shape of a normal red blood cell resembles a disk. Normal red blood cells easily change shape to move effectively through the small blood vessels between organs of the body. A person with spherocytosis has red blood cells that are very round and have difficulty changing this shape. The lack of ability to change shapes makes moving through the small blood vessels difficult. Therefore, the red blood cells stay in the spleen longer than normal. This lengthy stay in the spleen damages the cell membranes. Eventually, the spleen will destroy these abnormal red blood cells.