Appendicitis is swelling (inflammation) of the appendix. The appendix is a small pouch attached to the beginning of your large intestine.
Causes, incidence, and risk factors
Appendicitis is one of the most common causes of emergency abdominal surgery in the United States. It usually occurs when the appendix becomes blocked by feces, a foreign object, or rarely, a tumor.
The symptoms of appendicitis can vary. It can be hard to diagnose appendicitis in young children, the elderly, and women of childbearing age.
The first symptom is often pain around your belly button. (See: Abdominal pain) The pain may be minor at first, but it becomes more sharp and severe. Your appetite will be reduced, and you may have nausea, vomiting, and a low fever.
As the swelling in the appendix increases, the pain tends to move into your right lower abdomen. It focuses right above the appendix at a place called McBurney's point. This most often occurs 12 to 24 hours after the illness starts.
If your appendix breaks open (ruptures), you may have less pain for a short time and you may feel better. However, once the lining of your abdominal cavity becomes swollen and infected (a condition called peritonitis), the pain gets worse and you become sicker.
Your pain may be worse when you walk or cough. You may prefer to lie still because sudden movement causes pain.
Later symptoms include:
Signs and tests
If you have appendicitis, your pain will increase when the doctor gently presses on your lower right belly area. If you have peritonitis, touching the belly area may cause a spasm of the muscles.
A rectal exam may find tenderness on the right side of your rectum.
Doctors can usually diagnose appendicitis by:
Your description of the symptoms
The physical exam
In some cases, other tests may be needed, including:
If you do not have complications, a surgeon will usually remove your appendix soon after your doctor thinks you might have the condition. For information on this type of surgery, see: Appendectomy.
Because the tests used to diagnose appendicitis are not perfect, sometimes the operation will show that your appendix is normal. In that case, the surgeon will remove your appendix and explore the rest of your abdomen for other causes of your pain.
If a CT scan shows that you have an abscess from a ruptured appendix, you may be treated for infection. You will have your appendix removed after the infection and swelling have gone away.
If your appendix is removed before it ruptures, you will likely get well very soon after surgery. If your appendix ruptures before surgery, you will probably recover more slowly, and are more likely to develop an abscess or other complications.
Abnormal connections between abdominal organs or between these organs and the skin surface (fistula)
Blockage of the intestine
Infection inside the abdomen (peritonitis)
Infection of the surgical wound
Calling your health care provider
Call your health care provider if you have abdominal pain in the lower-right portion of your belly, or any other symptoms of appendicitis. Also call your doctor if:
Your pain is severe, sudden, or sharp
You have a fever along with your pain
You are vomiting blood or have bloody diarrhea
You have a hard abdomen that is tender to touch
You are unable to pass stool, especially if you are also vomiting
You have chest, neck, or shoulder pain
You are dizzy or light-headed
You have nausea and a lack of appetite with your pain
You are losing weight that you did not mean to lose
You have yellowing of your eyes or skin
You have bloating for more than 2 days
You have diarrhea for more than 5 days, or your infant or child has had diarrhea for 2 days or vomiting for 12 hours (call right away if a baby younger than 3 months has diarrhea or vomiting)
You have had abdominal pain for more than 1 week
You have burning with urination or you are urinating more often than usual
You have pain and may be pregnant
Your pain gets worse when you take antacids or eat something
Ben-David K, Sarosi GA Jr. Appendicitis. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger & Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 116.
Bundy DG, Byerley JS, Liles EA, Perrin EM, Katznelson J, Rice HE. Does this child have appendicitis? JAMA. 2007;298:438-451.
Krajewski S, Brown J, Phang PT, Raval M, Brown CJ. Impact of computed tomography of the abdomen on clinical outcomes in patients with acute right lower quadrant pain: a meta-analysis. Can J Surg. 2011;54:43-53.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.