Pathophysiology
Osmosis leads to the red blood cell having a constant tendency to swell and burst. This tendency is countered by manipulating the flow of sodium and potassium ions. A 'pump' forces sodium out of the cell and potassium in, and this action is balanced by a process called 'the passive leak'. In the hereditary stomatocytoses, the passive leak is increased and the cell becomes swamped with salt and water. The cell lyses and a haemolytic anaemia results. For as yet unknown reasons, the cells take on an abnormal shape, resembling a mouth or 'stoma'.
Read more about this topic: Hereditary Stomatocytosis