What is appendicitis?

Your appendix is a small finger-shaped tube, between 2 to 4 inches (5 to 10 centimeters) long, which is attached to the beginning of your large intestine. It is thought the appendix was used by our ancestors to break down cellulose in their diet, but is now generally thought to be an unnecessary or 'vestigial' organ.

Sometimes feces, a foreign body, infection, inflammation or mucus can block the appendix and cause it to swell up. This causes appendicitis, an infected swelling of the appendix. If this infected matter escapes through a perforation (hole) in the appendix wall, it can cause life-threatening complications.


A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.


A thick, viscous liquid that is secreted for lubrication and to form a protective lining over certain tissues.


Appendicitis is caused when the opening between the appendix and the large intestine becomes blocked. The bacteria that normally live within the appendix multiply, causing infection and inflammation. Pus starts to build up as your body tries to heal the infection. This puts great pressure on the appendix wall, causing pain and swelling.

Location of the appendix. 

The actual blockage of your appendix may be caused by any of the following:

  • Hardened fecal matter, food or other material that has built up and blocked the opening;
  • Enlarged lymphatic tissue - this is usually due to an infection elsewhere in the body, often the abdominal cavity;
  • Parasitic infestation or an abnormal growth blocking the entrance to the appendix, and;
  • Trauma to the abdominal area that causes inflammation.


A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Lymphatic tissue

Tissue rich in lymphocytes, small white blood cells that have specific immune responses, that makes up the lymphatic system.

Risk factors

There are no real risk factors for developing appendicitis, but it does occur more often in people under 30 years of age.

Signs and symptoms

Appendicitis symptoms can vary, but the following are commonly reported:

Abdominal pain

Appendicitis pain usually starts suddenly, behind your bellybutton. At first it comes and goes, but within a few hours, it tends to move to the lower, right-hand side of the abdomen, then becomes severe, sharp and constant. The pain can become sharper over a few hours and can be felt anywhere in the lower back or lower abdomen. Passing urine, taking deep breaths, walking, coughing or sneezing will usually make the pain worse. The location of the pain can vary, depending on your age and where your appendix is located. The appendix is located on the right side, but rarely, a long appendix may stretch to the left side.

Other symptoms are:

  • Nausea, vomiting and diarrhea;
  • Loss of appetite;
  • Low-grade fever with flushed face, and;
  • Swollen abdomen.


The part of the body that lies between the chest and the pelvis.

Methods for diagnosis

Your doctor will want to take a detailed medical history and perform a physical examination. Tests that can assist with the diagnosis of appendicitis include the following:

Laboratory tests

Blood tests

A blood test may be ordered by your doctor to check for signs of infection. If an infection is present, your white blood cell count may be increased.

Urine analysis

Testing your urine can help identify conditions affecting the urinary tract, such as a urinary tract infection or kidney stones, which may cause similar symptoms to appendicitis.

Pregnancy test

In women of child-bearing age, your doctor may want to rule out the possibility of an ectopic pregnancy.

Imaging tests

Computerized tomography

A computerized tomography (CT) scan can be used to take cross-sectional images of your abdomen, especially if your doctor is unsure of your diagnosis. It can help rule out other causes of pain in some circumstances.


An ultrasound is especially useful in children. This test is less accurate than CT for confirming appendicitis, but does not pose any radiation risks. Ultrasound may also help in diagnosing other causes in women, such as ectopic pregnancy and ovarian cysts.

Abdominal X- ray

An X-ray can occasionally help identify other causes of the pain, such as constipation.


The part of the body that lies between the chest and the pelvis.

Computerized tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.


A scan that uses ionizing radiation beams to create an image of the body’s internal structures.

Types of treatment

If you have been diagnosed with appendicitis, the most common treatment will be an appendectomy, the surgical removal of the appendix. There are two ways of having this surgery: open surgery or keyhole surgery.

Keyhole surgery

Keyhole surgery (also called laparoscopic surgery) is much less invasive than open surgery and is the preferred option in most adults. Under a general anesthetic, a number of small incisions (cuts) are made in your abdomen. Through these incisions, your surgeon will use a slender camera (laparoscope) to help visualize the removal of the appendix, which is done using fine surgical instruments. This eliminates the need for a large abdominal cut and speeds up healing.

Keyhole appendectomy, removal of appendix via keyhole, before and after appendectomy.The removal of the appendix via keyhole surgery. 

Open surgery

Your doctor may prefer open surgery over keyhole in the following situations:

  • If you are in your third trimester of pregnancy;
  • If you are very young;
  • If you have an infection or abscess that may have spread throughout your abdominal cavity. Your doctor may need a better view to see what areas need attention;
  • If you have a tumor in your digestive system, and;
  • If you have had previous abdominal surgeries.

Delaying surgery

In some rare circumstances, your doctor may recommend treating you with antibiotics to reduce the size of your appendix prior to surgery. A drainage tube may be inserted if you have an abscess, to drain away the contents and clear the infection. Surgery may then be attempted at a later date.


Intravenous antibiotics are used to help treat the infection, in addition to surgery. These may be ceased after the successful removal of the infected appendix. Your doctor can advise if you will need a course of oral antibiotics when you are discharged.


The part of the body that lies between the chest and the pelvis.

General anesthetic

An anesthetic given to a person to put them to sleep while having an operation or medical procedure. Afterwards, the person regains consciousness and usually has no memory of the procedure. A general anesthetic is given in hospital by a specialist called an anesthetist.


A growth caused by an abnormal and uncontrolled reproduction of cells.

Potential complications


If your appendix ruptures it can cause peritonitis, a life-threatening infection of your pelvic cavity. This occurs when the pus and infected material inside the appendix leaks out, infecting the lining of your pelvic cavity. This can lead to a blood infection (septicemia) if untreated. Peritonitis is a medical emergency and requires urgent hospital treatment.

Warning signs to look out for are:

  • Swelling of your abdomen with severe continuous pain;
  • Inability to walk or move due to pain;
  • A high temperature, and;
  • Rapid shallow breathing and a racing heartbeat.

Burst abscess

Sometimes a collection of pus (an abscess) will form around your infected appendix. The pus will need to be removed using surgery or a drainage tube, to prevent it bursting and spreading the infection within the abdominal cavity. You will be given antibiotics to fight any infection and the appendix will need to be removed either immediately, or as a delayed procedure (see 'Delaying surgery').


The part of the body that lies between the chest and the pelvis.

Pelvic cavity

The space within the pelvis, the bony structure in the lower part of the body trunk, which contains the bladder, reproductive organs in females, and the lower intestines.


Once your appendectomy has been completed, you can expect to recover within 7-28 days. The outlook for recovery is generally good, as long as treatment was not delayed and your appendix did not burst prior to removal, both of which can cause complications. Factors that can affect the recovery time include your general physical condition, age, complications and lifestyle choices such as smoking and alcohol consumption.

It is important that suspected cases of appendicitis are treated quickly. Severe complications and death from appendicitis are unusual but may occur, especially if peritonitis is left untreated.


There is no known way of preventing appendicitis.


  1. Acute appendicitis in adults: Diagnostic evaluation. Accessed 6 October 2014 from link here
  2. Appendectomy | Johns Hopkins Medicine Health Library. Accessed 6 October 2014 from link here
  3. Appendicitis | Better Health Channel. Accessed 6 October 2014 from link here
  4. Appendicitis - NHS Choices. Accessed 6 October 2014 from link here
  5. Chronic and recurrent appendicitis are uncomm... [J Am Coll Surg. 1994] - PubMed - NCBI. Accessed 6 October 2014 from link here

FAQ Frequently asked questions