The appendix usually “bursts” because an infection called appendicitis is not treated in time. This infection makes the appendix swell, fill with pus, and eventually tear or rupture if pressure keeps building up.
Main cause
Most burst appendixes start with a blockage of the small opening inside the appendix, which leads into the large intestine. Common things that block it include hardened stool (a fecalith), swollen lymph tissue after an infection, parasites, or rarely tumors or foreign material. Once blocked, mucus and bacteria get trapped, the appendix swells, and pressure inside it rises.
How it progresses to a rupture
As pressure increases, blood flow to the appendix wall decreases, so the tissue becomes weak, ischemic (starved of blood), and starts to die. Bacteria and pus build up, stretching the wall until it perforates, which is what people call the appendix “bursting.” When it ruptures, infected material leaks into the abdominal cavity and can cause peritonitis or abscesses, which are life‑threatening without urgent treatment.
Risk and timing factors
A rupture is much more likely if appendicitis symptoms go untreated for 24–72 hours or longer, because the infection and pressure have more time to damage the wall. Children and older adults may be at higher risk of perforation because symptoms can be vague or noticed later, so diagnosis and treatment are sometimes delayed. Certain conditions that increase inflammation in the abdomen, like inflammatory bowel disease or recurrent pelvic infections, may also raise the chance of appendicitis progressing to a rupture.
What doesn’t cause a burst appendix
Normal activities like walking, exercise, or jumping do not by themselves make a healthy appendix burst; the underlying problem is the obstruction and infection. A sudden reduction in pain after severe appendicitis symptoms can actually mean the appendix has already ruptured, and this is a medical emergency, not a sign that the problem has gone away.
When to seek help
Warning signs that may suggest appendicitis (and the risk of rupture) include pain that often starts near the belly button and moves to the lower right side, worsening with time, along with fever, nausea, or loss of appetite. Anyone with these symptoms should get urgent medical evaluation, because early removal of an inflamed appendix greatly reduces the chance that it will burst.
