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Pronounced: Ah-PEN-de-SITE-is

En Español (Spanish Version)


Appendicitis is inflammation of the appendix. The appendix is a small, tube-like organ that hangs from the large intestine. It appears to have no clear function.


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Appendicitis usually occurs when the appendix becomes inflamed. This can be caused by something trapped in the appendix, such as:

  • A piece of dried stool
  • A piece of food
  • Tumors
  • Scar tissue
  • Worms
  • Barium after a diagnostic exam
  • Overgrowth of the lymph tissue of the appendix

The lining of the appendix continues to produce mucus, but it has no place to go. Bacteria normally found in the intestines multiply and make toxins in the lining of the appendix. Pressure builds and causes severe pain in the abdomen. The wall of the appendix can break open. If the appendix ruptures, its contents can spill into the abdominal cavity. This causes serious inflammation in the abdominal cavity called peritonitis , which can be fatal.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

  • Sex: Male
  • Age: Teen years
  • Family members who have had appendicitis


Symptoms usually come on suddenly. Pain generally increases during a 6- to 12-hour period. Patients may experience some or all of the following symptoms:

  • Pain
    • Starts as discomfort around the belly button
    • Usually moves to the right side of the abdomen over several hours
    • May be in a different location if the appendix is not in the usual place
    • Increases as inflammation in the appendix builds
    • Worsens with sneezing, coughing, and deep breathing
    • May increase with movement
  • Loss of appetite
  • Nausea
  • Vomiting
  • Swelling of the abdomen
  • Abdomen feels hard and is sensitive to touch
  • Constipation
  • Mild diarrhea
  • Slight fever

If the appendix ruptures, symptoms include:

  • Pain becoming stronger and spreading across the abdomen
  • Increasing fever

Note: Symptoms may be atypical in infants, children, pregnant women, and the elderly.


Seek immediate medical care if you have severe pain in the abdomen. Appendicitis can be hard to diagnose. Symptoms vary and can be similar to symptoms of other diseases.

The doctor will ask about your symptoms and medical history, and perform a physical exam. The exam will include:

  • A careful examination of the abdomen
  • A rectal exam

Other tests to determine the cause of your pain may include:

  • Blood tests—to see if you have an infection
  • Urine tests—to rule out urinary tract infection
  • CT scan or ultrasound—These tests, which are only helpful in cases of late appendicitis, are used to look for signs of an inflamed appendix or abscess that may be causing the pain.
  • Laparoscopy—A thin, lighted tube is inserted through a small incision near the belly button.


Appendicitis is treated by surgically removing the appendix as soon as possible. If the diagnosis is not certain, the doctor may carefully monitor your condition for 6 to 12 hours before operating. You will also be given antibiotics to fight infection.

Although this is still considered the standard of care, a recent study investigated the safety and effectiveness of treating appendicitis with antibiotics instead of surgical appendectomy. Researchers divided 252 men diagnosed with acute appendicitis into two groups: immediate surgery or intravenous antibiotics with surgery only if symptoms persisted for more than 24 hours. Eighty-six percent of patients in the antibiotics group improved without surgery and only 14% of these patients had recurrent symptoms of appendicitis within one year. * Although most surgeons will continue to recommend prompt appendectomy if they suspect appendicitis, if additional research confirms these findings, selected patients may be able to safely avoid surgery in the future.


There are no guidelines for preventing appendicitis because it comes on suddenly and the cause is usually not known. To decrease the risk of rupture, seek medical care immediately for severe abdominal pain.


American College of Surgeons

National Digestive Diseases Information Clearinghouse


BC Health Guide

Canada Health Portal


American College of Surgeons website. Available at: . Accessed October 13, 2005.

Dambro MR. Griffith's 5-Minute Clinical Consult. Philadelphia, PA: Lippincott Williams & Wilkins; 1999.

Diagnosis of appendicitis in emergency departments. Am Fam Physician. 2003;67:2390.

Emergency Medicine: Concepts and Clinical Practice. 4th ed. Philadelphia, PA: Mosby-Year Book, Inc; 1998.

Feldman M, Scharschmidt BF, Sleisenger MH. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 6th ed. Philadelphia, PA: WB Saunders Company; 1998.

JAMA patient page: appendicitis JAMA. 1999;282:1102.

National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: . Accessed October 13, 2005.

Sabiston DC Jr. Textbook of Surgery. 15th ed. Philadelphia, PA: WB Saunders Co.; 1997.

*Updated Treatment section on 7/13/2007 according to the following study, as cited by DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Styrud J, Eriksson S, Nilsson I, et al. Appendectomy versus antibiotic treatment in acute appendicitis. a prospective multicenter randomized controlled trial. World J Surg. 2006;30:1033-1037.

Last reviewed December 2007 by Jill Landis, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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