What is appendicitis?

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Appendicitis is a condition that results from inflammation of the appendix. The appendix is a blind ending (closed) tube of tissue attached to the large intestine in the lower right part of the abdomen. Inflammation occurs when the appendix becomes infected or blocked. Blockages can be the result of:

  • stool
  • foreign bodies (objects or substances that have been introduced from the outside)
  • a tumor

An early symptom of appendicitis is pain, often in the center of the abdomen but sometimes on the right side. The pain may be dull at first, but may become more sharp or severe. Accompanying symptoms may include slight fever (above normal but less than 100 degrees), vomiting or nausea.

Some individuals, particularly children, experience loss of appetite.

As the condition progresses, severe pain is usually felt in the lower right part of the abdomen.

As the appendix becomes further inflamed, symptoms may include:

  • severe or worsening pain or cramping in the abdomen, rectum or back
  • swelling or tenderness in the abdomen
  • severe nausea or vomiting
  • high fever (over 100 degrees)
  • diarrhea or constipation
  • inability to expel gas

Appendicitis can be difficult to diagnose because a number of other conditions can cause similar symptoms. Not everyone with appendicitis exhibits all of these symptoms. If you have any of these symptoms, particularly abdominal pain that continues to worsen, contact your doctor immediately.

How is appendicitis evaluated?

Several tests can be used to evaluate appendicitis:

  • Abdominal ( or pelvic ultrasound ( may be performed. Ultrasound is a type of imaging exam that uses sound waves to create pictures of the inside of the abdomen and/or pelvis.

    For information about ultrasound procedures performed on children, visit the Pediatric Abdominal Ultrasound page (

  • A CT scan of the abdomen and pelvis ( may be performed. During a CT scan, x-rays are used to capture pictures of the inside of the abdomen and pelvis.

    For information on CT scans performed on children, visit the Pediatric CT page (

  • In young patients or women who are pregnant, MRI of the pelvis ( may be performed. MRI obtains pictures of the body using a strong magnet.
  • In some cases, an abdominal or chest x-ray ( may be the initial imaging study. Constipation and sometimes even pneumonia may be causing abdominal pain similar to that seen with appendicitis.

How is appendicitis treated?

The most common treatment for appendicitis is an appendectomy, or surgery to completely remove the appendix. However, in some patients, the appendix can rupture and lead to an abscess, or collection of pus. If this is the case, your doctor may recommend having a percutaneous abscess drainage procedure ( to remove the fluid from your body in addition to undergoing an appendectomy. Patients who undergo percutaneous abscess drainage will remain hospitalized for a few days. Follow up is usually done on an outpatient basis and you will be seen by your interventional radiologist to make sure healing is proceeding according to plan.

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This page was reviewed on May 16, 2014

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