Appendicitis is an inflammation of the appendix, a 3 1/2-inch-long tube of tissue that extends from the large intestine. One study suggests that the appendix may have some role in gut immunity, but nothing is definite. One thing we do know: We can live without it, without apparent consequences.
Appendicitis is a medical emergency that almost always requires prompt surgery to remove the appendix. Left untreated, an inflamed appendix will eventually burst, or perforate, spilling infectious materials into the abdominal cavity. This can lead to peritonitis, a serious inflammation of the abdominal cavity’s lining (the peritoneum) that can be fatal unless it is treated quickly with strong antibiotics.
Sometimes a pus-filled abscess (infection that is walled off from the rest of the body) forms outside the inflamed appendix. Scar tissue then “walls off” the appendix from the rest of the abdomen, preventing infection from spreading. An abscessed appendix can perforate or explode and cause peritonitis. For this reason, almost all cases of appendicitis are treated as emergencies, requiring surgery.