Spherocytosis, in most cases, is an inherited disease that changes the shape of and decreases the life of red blood cells. This destruction of the red blood cells leads to anemia.

The shape of a normal red blood cell looks like a disk. Normal red blood cells are flexible and change shape with ease to move smoothly through the small blood vessels between organs of the body.

A person with spherocytosis has red blood cells that are very round and have trouble changing this shape. This makes moving through the small blood vessels hard. So, the red blood cells stay in the spleen longer than normal. This lengthy stay in the spleen harms the cell membranes. Eventually, the spleen destroys these abnormal red blood cells.