Appendicitis is inflammation of the vermiform appendix (or just the appendix, for short), a little structure within the lower gastrointestinal tract.
In appendicitis, the appendix swells, causing a condition that is classified as either acute or chronic. Both acute and chronic appendicitis are characterized by some of the same symptoms, especially abdominal pain. However, while chronic appendicitis features pain that waxes and wanes over periods of weeks, months or years, and that tends to be milder, acute appendicitis has symptoms that are more severe and emerge rapidly, typically over 12 to 24 hours.
