Appendicitis is a painful swelling and infection of the appendix.

What is the appendix?

The appendix is a fingerlike pouch attached to the large intestine and located in the lower right area of the abdomen. Scientists are not sure what the appendix does, if anything, but removing it does not appear to affect a person’s health. The inside of the appendix is called the appendiceal lumen. Mucus created by the appendix travels through the appendiceal lumen and empties into the large intestine.



What causes appendicitis?

Obstruction of the appendiceal lumen causes appendicitis. Mucus backs up in the appendiceal lumen, causing bacteria that normally live inside the appendix to multiply. As a result, the appendix swells and becomes infected. Sources of obstruction include

  •  feces, parasites, or growths that clog the appendiceal lumen
  •  enlarged lymph tissue in the wall of the appendix, caused by infection in the gastrointestinal tract or elsewhere in the body
  •  inflammatory bowel disease, including Crohn’s disease and ulcerative colitis
  •  trauma to the abdomen

An inflamed appendix will likely burst if not removed. Bursting spreads infection throughout the abdomen—a potentially dangerous condition called peritonitis.


Who gets appendicitis?

Anyone can get appendicitis, but it is more common among people 10 to 30 years old. Appendicitis leads to more emergency abdominal surgeries than any other cause.


What are the symptoms of appendicitis?

Most people with appendicitis have classic symptoms that a doctor can easily identify. The main symptom of appendicitis is abdominal pain.


The abdominal pain usually

  •  occurs suddenly, often causing a person to wake up at night
  •  occurs before other symptoms
  •  begins near the belly button and then moves lower and to the right
  •  is new and unlike any pain felt before
  •  gets worse in a matter of hours
  •  gets worse when moving around, taking deep breaths, coughing, or sneezing


Other symptoms of appendicitis may include

  •   loss of appetite
  •   nausea
  •   vomiting
  •   constipation or diarrhea
  •   inability to pass gas
  •  a low-grade fever that follows other symptoms
  •   abdominal swelling
  •   the feeling that passing stool will relieve discomfort


Symptoms vary and can mimic other sources of abdominal pain, including

  •  intestinal obstruction
  •   inflammatory bowel disease
  •   pelvic inflammatory disease and other gynecological disorders
  •   intestinal adhesions
  •   constipation