What Causes Appendix to Burst? Doctor Explains.

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Summary: causes of burst appendix:

The leading causes of a burst appendix are obstruction and pressure build-up, bacterial infection, and appendix wall gangrene. In addition, delayed diagnosis or treatment of appendicitis raises the risks of a burst appendix.

Here is a summary of the causes:

  • Time (delayed diagnosis and treatment of acute appendicitis).
  • Appendix obstruction (be a hard stool, stone, or swollen lymphatics).
  • Appendix infection (bacteria build-up inside the appendix).
  • Appendix gangrene (obstruction of the blood supply of the appendix leads to necrosis (death) of its wall).
  • Others such as pain control medications which delay the diagnosis, dementia, and psychiatric diseases.

1. Time is the most critical cause of burst appendix.

Appendicitis is a rapid and progressive inflammation. A delay in seeking medical advice, diagnosis, or treatment will increase the risk of a burst appendix.

The early diagnosis and treatment of appendicitis is the most important factor that minimizes the risk of a burst appendix.

According to one study, the duration between the symptom and Emergency department arrival is crucial. The more time it passes, the more risk of burst appendix you get (reference).

The study estimated that you have a 2.5 more risk of burst appendix if more than 24 hours pass without getting to the hospital.

Why is time critical in preventing burst appendix?

The appendix gets inflamed due to its obstruction (by a stool matter, stone, or edema from inflammation.

Once obstruction occurs, bacteria and mucus builds up rapidly inside the obstructed appendix. As time passes, the pressure inside the appendix increases.

Increased pressure leads to a decreased blood supply to the appendix wall. As a result, death of the appendix tissues occurs (gangrene) due to the obstruction of blood supply.

The more time passes, the more pressure build-up and gangrene development in the appendix wall. That’s why time is the most significant cause of a burst appendix.

In another study, 65% of the cases of burst appendix had symptoms for more than 48 hours. Moreover, only 20% of the cases of burst appendix occurred in the first 24 hours (reference).

MORE: Burst Appendix: Survival Rate, Complications & symptoms.

2. Appendix obstruction by a fecalith or appendix stone.

Appendix obstruction is often the trigger event of appendicitis. The obstruction of the appendix can be the starting event of appendicitis or can develop later during the inflammation process.

Causes of appendix obstruction include (reference):

  • Fecalith: hard mass of poop (feces).
  • Appendix stone: An old calcified feces forming a hard stone in the appendix.
  • Enlargement (hyperplasia) of the lymphoid tissue at the appendix.
  • Infections: bacteria infection triggers swelling of the tissues leading to the obstruction of its cavity.
  • Tumors of the appendix (benign or malignant).
  • Fibrosis.
  • Seeds.

Hard stool masses (fecalith) are more common inside the appendix than actual appendix stones.

However, One study found that appendix stones have a higher tendency to cause burst appendix than fecalith (reference).

The incidence of burst appendix with fecalith and appendix stones was 19% and 45%, respectively.

Once the obstruction of the appendix occurs, the mucus and bacteria build-up increases inside the appendix lumen.

Obstruction leads to distension of the lumen and increased pressure which aids in the burst process.

Moreover, the obstruction and the pressure build-up presses on the blood vessels supplying the appendix wall. Compressed blood vessels ultimately lead to gangrene in the appendix wall, increasing the odds of rupture (reference).

MORE: Can Constipation Cause Appendicitis?

3. Bacteria build up inside the appendix.

Bacterial infection is an essential factor in abscess formation and perforation of the appendix.

Bacterial infection can be the trigger event of appendicitis. Which then leads to obstruction of the appendix due to the inflammation and swelling of the appendix.

Also, Bacterial infections can occur later as a result of an obstruction to the appendix. Therefore, combined infection and obstruction of the appendix are the two most important mechanisms of a burst appendix.

Infection and inflammation are found in nearly 90% of all cases of acute appendicitis. But not all cases of disease lead to a burst appendix.

Infections also play a role in cutting the blood supply to the appendix tissue (appendix gangrene). In addition, the infection triggers inflammation and swelling of the appendix, which compresses the blood vessels of the appendix.

4. Appendix gangrene.

Gangrene is the death of the tissues of the appendix wall. In addition, appendix gangrene carries a high risk of appendicular rupture.

Gangrene occurs due to the cutting of the blood supply to the appendix wall. It is often due to the external compression on the small blood vessels of the appendix wall.

The external compression is due to:

  • Obstruction of the appendix and pressure build-up on the blood vessels on the appendix wall.
  • Infections trigger swelling, which in turn compresses the appendix.
  • Tumors of the appendix.
  • A large mass of feces (fecalith).

Also, thrombosis of the blood obstruction the vessel from inside can occur due to severe inflammation (reference).

With gangrene, the tissue of the appendix wall is dead and brittle.

5. Other causes and risk factors of a burst appendix.

  • Pain control medications can mask the symptoms and delays the diagnosis. The delay in diagnosis is a significant risk factor of a burst appendix.
  • Elderly with dementia.
  • People with psychiatric diseases such as schizophrenia (reference).

Bonus: Symptoms of a burst appendix.


  • High-grade fever: temperature exceeds 103.0°F (39.4°C).
  • Initial temporary relief (due to the relief of pressure inside the appendix lasts for minutes to few hours.
  • The pain becomes generalized all over your abdomen.
  • Severe tenderness on touching the abdomen.
  • Fast heartbeats.
  • Rapid and shallow breathing.
  • White blood cell count more than 15,000
  • Low blood pressure.
  • A fluid collection around the appendix.