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What Is Appendicitis?

Maybe your side hurt so much that you called your healthcare provider. Or maybe you went straight to the hospital emergency room. If the symptoms came on quickly, you may have appendicitis. This is an inflammation or infection of the appendix. Treatment should start right away to prevent serious problems.

Your appendix

The appendix is a hollow pouch about the size of your little finger. It hangs off the colon (large intestine). The purpose of the appendix is unclear. There are theories that the appendix is a storehouse for good bacteria in the gut. But if it becomes blocked, it may become infected.

Outline of abdomen showing small intestine and colon.

Symptoms of appendicitis

Symptoms tend to appear quickly, often over 1 to 2 days. Symptoms can include:

  • Pain that starts in the center of your belly and moves to your lower right side

  • Increased pain and pressure on your side when you walk

  • Vomiting, nausea, or decreased appetite

  • Fever or fatigue

  • Either diarrhea or constipation


  • Antibiotic therapy. In some cases, your healthcare provider may advise treatment with antibiotics. This is if the appendix has not ruptured and you don't have other problems or risks. Using antibiotics helps keep you from needing surgery.

  • Surgery. Treating appendicitis with surgery (appendectomy) is the most common and often the best choice. This is a very common procedure. Removing the appendix should not affect your long-term health. It’s best to remove the appendix before it bursts. If a burst appendix isn't removed, it can cause severe health problems.

© 2000-2022 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.