The appendix is a small finger-like appendage found near the juncture of the small and large intestines. Also termed the vermiform appendix, the organ is vestigial and has no apparent function. Vestigial organs and structures are those that do not serve an anatomical or physiological purpose and which are considered evolutionary remnants of an ancestral species or nonfunctional remnants of organs and structures created during embryonic development. Despite the fact that the appendix is not essential to good health, appendicitis--an inflammation of the appendix--can be life threatening and usually requires surgery to remove the appendix.

Inflammation of the appendix in the form of appendicitis may cause the appendix to rupture and spill its contents, including intestinal bacteria into the peritoneal cavity. As a result of the introduction of intestinal bacteria into the peritoneum, an individual usually develops peritonitis, an inflammation of the peritoneum or peritoneal cavity. The peritoneal cavity is the space separating the visceral and parietal layers of the peritoneum. Peritonitis results in a high fever, pain, and may result in death if not aggressively treated with antibiotics.

During the course of digestion and waste elimination, the appendix may become clogged with fecal matter. Such a blockage prevents the normal drainage from the appendix and may result in acute (rapid onset) inflammation. Other agents, including parasitic worms, may also block appendix drainage and result in appendicitis.

The appendix is located in the lower right portion of the abdomen. Inflammation of the appendix is usually accompanied by a painful tenderness in this region, especially in response to palpation (the exerting of pressure by the hand). It is not uncommon for patients to experience pain in other areas, especially when the appendix becomes severely inflamed or ruptures.