Appendicitis is inflammation and infection of the appendix.
Often a blockage inside the appendix causes the appendix to become inflamed and infected.
Abdominal pain, nausea, and fever are common.
Exploratory surgery or an imaging test, such as computed tomography or ultrasonography, is done.
Treatment involves surgery to remove the appendix and antibiotics to treat the infection.
(See also Acute Abdominal Pain.)
The appendix is a small finger-shaped tube projecting from the large intestine near the point where it joins the small intestine. The appendix may have some immune function, but it is not an essential organ.
Appendicitis is the most common cause of sudden, severe abdominal pain and abdominal surgery in the United States. Over 5% of the population develops appendicitis at some point. Appendicitis most commonly occurs during adolescence and in the 20s but may occur at any age.
The cause of appendicitis is not fully understood. However, in most cases, a blockage inside the appendix probably starts a process. The blockage may be from a small, hard piece of stool (fecalith), a foreign body, or, rarely, even worms. As a result of the blockage, the appendix becomes inflamed and infected. If inflammation continues without treatment, the appendix can rupture. A ruptured appendix may cause a pus-filled pocket of infection (abscess) to form. As a result, peritonitis (inflammation and usually infection of the abdominal cavity, which may result in a life-threatening infection) may develop. In a woman, the ovaries and fallopian tubes may become infected, and the resulting scarring may block the fallopian tubes and cause infertility. A ruptured appendix also may allow bacteria to infect the bloodstream—a life-threatening condition called sepsis.
