Definition & Facts for Appendicitis

In this section:

What is appendicitis?

Appendicitis is inflammation of your appendix, a finger-like pouch attached to your large intestine. The appendix is in the lower-right area of your abdomen, or belly.

Illustration of the abdomen showing position of the appendix and colon.Your appendix is in the lower-right area of your abdomen, near where the small intestine attaches to the large intestine.

How common is appendicitis?

In the United States, appendicitis is the most common cause of acute abdominal pain for which you need surgery. About 5 to 9 of every 100 people develop appendicitis at some point.1

Who is more likely to develop appendicitis?

Appendicitis is slightly more common among males than females. It happens more often in people in their teens and 20s, but it may happen in people of any age, including older adults.1

What are the complications of appendicitis?

Untreated appendicitis can cause your appendix to burst. A burst appendix could lead to complications. One such complication, peritonitis, is a serious infection that can spread in your abdomen. Another possible complication is an abscess of the appendix called an appendiceal abscess.

References

Last Reviewed July 2021
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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.