When your appendix becomes infected or obstructed, bacteria that normally live inside of the organ can multiply rapidly.
Your appendix becomes inflamed and filled with pus, a thick liquid containing bacteria, tissue cells, and dead white blood cells.
This infection will cause pressures within your appendix to quickly increase.
As the pressures increase, the amount of blood flowing through the wall of the organ decreases. The tissues of your appendix will then become starved of blood and start to die.
This will continue until the muscular wall in one area of your appendix gets so thin that it breaks open, allowing bacteria-laden pus from inside the appendix to ooze out into the rest of the abdomen.