The appendix (vermiform appendix) is a blind extension of the bowel in the lower right abdomen. Appendicitis occurs when the entrance to the appendix becomes blocked and infection sets in. If the appendix ruptures (perforates) infection spreads thoughout the abdomen (peritonitis) which is fatal without antibiotics and expert care. Because of the risk of this happening and often a prolonged illness otherwise, surgery (appendicectomy) when available is the best treatment.
Appendicitis caused 0.04% of all deaths worldwide in 2002, an average of 3 deaths per million people per year.