Appendicitis is an inflammation of the appendix. The appendix is a finger-shaped pouch that sticks out from the colon on the lower right side of the belly, also called the abdomen.

Appendicitis causes pain in the lower right abdomen. However, in most people, pain begins around the belly button and then moves. As inflammation worsens, appendicitis pain typically increases and eventually becomes serious.

Although anyone can develop appendicitis, most often it occurs in people between the ages of 10 and 30. Treatment of appendicitis is usually antibiotics and surgery to remove the appendix.


Symptoms of appendicitis may include:

  • Sudden pain that begins on the right side of the lower abdomen.
  • Sudden pain that begins around the navel and often shifts to the lower right abdomen.
  • Pain that worsens with coughing, walking or making other jarring movements.
  • Nausea and vomiting.
  • Loss of appetite.
  • Low-grade fever that may rise as the illness worsens.
  • Constipation or diarrhea.
  • Abdominal bloating.
  • Gas.

The site of the pain may vary, depending on age and the position of the appendix. In pregnancy, the pain may seem to come from the upper abdomen because the appendix is higher during pregnancy.

When to see a doctor

Make an appointment with your health care team if you or your child has symptoms. Terrible abdominal pain requires immediate medical attention.


A blockage in the lining of the appendix is the likely cause of appendicitis. This blockage can cause an infection. The bacteria then multiply quickly, causing the appendix to become inflamed, swollen and filled with pus. If not treated right away, the appendix can break open.


Appendicitis can cause serious complications, such as:

  • A burst appendix. A burst appendix, also called ruptured appendix, spreads infection throughout the abdomen, a condition called peritonitis. Possibly life-threatening, this condition requires immediate surgery to remove the appendix and clean the abdominal cavity.
  • A pocket of pus that forms in the abdomen. If your appendix bursts, you may develop a pocket of infection, called an abscess. In most cases, a surgeon drains the abscess by placing a tube through your abdominal wall into the abscess. The tube is left in place for about two weeks, and you're given antibiotics to clear the infection.

    Once the infection is clear, you'll have surgery to remove the appendix. In some people, the abscess is drained, and the appendix is removed immediately.