Appendicitis is inflammation of the appendix. The appendix is a small, tube-like organ that hangs from the large intestine. It has no known function.

This problem needs to be treated right away. Appendicitis can result in the appendix bursting and releasing its contents into the belly. This can lead to a serious infection that can be deadly.

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The exact cause is not known. It is thought to be caused by something trapped in the appendix, such as:

  • Stool (poop)
  • A piece of food
  • Tumors
  • Scar tissue
  • Overgrowth of the lymph tissue of the appendix

Risk Factors

This problem is more common in people who are 10 to 30 years of age. The environment may also play a role since this problem happens more often in the summer months.

Other things that may raise the risk are:

  • A family history of appendicitis
  • Infections



Pain is the most common problem. The pain may:

  • Start as discomfort around the belly button before moving to the right side of the belly
  • Gradually get worse over time
  • Worsen when moving, sneezing, coughing, or deep breathing

Other problems may be:

  • Loss of appetite
  • Nausea and vomiting
  • Abdominal swelling
  • A hard abdomen that hurts when it is touched
  • Constipation
  • Diarrhea
  • Fever

If the appendix bursts, problems may be:

  • Severe pain that spreads across the abdomen
  • Increasing fever

Note: Symptoms may be different in infants, children, older adults, and people who are pregnant.


The doctor will ask about your symptoms and health history. A physical will be done. It will focus on the abdomen. This may be enough to suspect appendicitis.

Blood and urine tests may be done to look for changes.

Images may be taken of the belly. This can be done with:

  • CT scan
  • Ultrasound
  • MRI scan

If the diagnosis is not clear, a surgery called a laparoscopy may be done to view inside the abdomen.



The appendix will need to be removed through surgery. This is called an appendectomy . It is usually done as soon as possible.


There are no known ways to prevent this health problem.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.


American College of Surgeons 

National Institute of Diabetes and Digestive and Kidney Diseases 


Alberta Health 

Health Canada 


Appendectomy. American College of Surgeons website. Available at: Accessed September 15, 2021.

Appendicitis. Merck Manual Professional Version website. Available at: Accessed September 15, 2021.

Appendicitis. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: Accessed September 15, 2021.

Appendicitis in adolescents and adults. EBSCO DynaMed website. Available at: Accessed September 15, 2021.