If you have appendicitis, your appendix becomes inflamed and fills with pus, creating pressure that worsens over hours. Without treatment, the appendix can rupture, spilling infection into your abdominal cavity. The lifetime risk of developing appendicitis is roughly 8.6% for males and 6.7% for females, with most cases striking between ages 10 and 30. Here’s what actually happens inside your body, how it’s caught, and what treatment and recovery look like.
What’s Happening Inside Your Body
Appendicitis starts when something blocks the narrow opening of your appendix. In younger people, the most common culprit is swollen lymph tissue triggered by an infection, even something as routine as a respiratory illness or stomach bug. In older adults, the blockage is more often a fecalith: a small, hardened mass of calcium salts and fecal debris that forms inside the appendix.
Once blocked, the appendix keeps producing mucus with nowhere for it to go. Bacteria already living inside begin to multiply rapidly. White blood cells rush in, pus builds up, and internal pressure climbs. Eventually that pressure exceeds what the tiny blood vessels in the appendix wall can handle. Blood flow gets cut off, the tissue starts to die, and bacteria invade through the weakened wall. Within hours, this can progress to a perforation, where the appendix tears open.
How the Pain Starts and Moves
The earliest symptom is usually a dull ache around your belly button. Over the next several hours, the pain migrates to the lower right side of your abdomen and sharpens. This migration pattern is one of the most telling signs. The pain tends to get worse with movement, coughing, or even hopping on one foot.
Alongside the pain, you may notice:
- Loss of appetite, often one of the first signs
- Nausea or vomiting that starts after the pain begins
- Low-grade fever that rises as inflammation worsens
- A swollen or bloated belly, which can signal the appendix has ruptured
Not everyone follows this textbook pattern. Children, pregnant women, and older adults sometimes have vague or unusual symptoms, which is one reason appendicitis can be tricky to diagnose in those groups.
How Doctors Confirm It
A physical exam is the first step. Your doctor will press on a spot called McBurney’s point, located in the center of your lower right abdomen about 3 to 4 centimeters toward your midline from your hip bone. Sharp tenderness there is a strong indicator. They may also press deeply on the left side of your abdomen; if that triggers pain on the right side (called Rovsing’s sign), it adds further suspicion. Another test involves lifting your right leg against resistance while lying flat. If this causes abdominal pain, the inflamed appendix is likely pressing against a nearby muscle.
When the exam is suggestive but not conclusive, imaging fills in the gaps. CT scans are the most common tool in adults, with roughly 94% sensitivity and 95% specificity for detecting appendicitis. Ultrasound is preferred for children and pregnant women to avoid radiation exposure, and it performs well too, with accuracy around 95% in experienced hands. Some hospitals use a staged approach: ultrasound first, then CT only if the results are unclear. That combination has been shown to reach 99% sensitivity.
What Happens If It Ruptures
The risk of perforation climbs steadily the longer appendicitis goes untreated. Research published in BJS Open found a perforation rate of about 2% per hour after diagnosis, with a median time to rupture of roughly 25 hours. Certain factors speed this up significantly. If a hardened fecalith is visible on the CT scan combined with high levels of inflammation, the perforation rate jumps to about 6% per hour, and the median time to rupture drops to around 8 hours.
A ruptured appendix can lead to three increasingly dangerous complications. First, an abscess (a walled-off pocket of pus) or a phlegmon (a solid inflammatory mass) may form around the appendix. These contain the infection temporarily but can burst. Second, if infection escapes into the abdominal cavity, it causes peritonitis, a serious and painful inflammation of the abdominal lining. Third, if bacteria reach the bloodstream, the result is sepsis, a life-threatening condition that can progress to organ failure.
Surgery: Laparoscopic vs. Open
The standard treatment is surgical removal of the appendix, called an appendectomy. Most are performed laparoscopically, through three small incisions each about 1 centimeter (roughly half an inch) long. The traditional open approach uses a single incision of about 5 centimeters (2 inches) in the lower right abdomen. Open surgery is sometimes necessary for complicated cases, such as when the appendix has already ruptured or an abscess has formed.
A large Cochrane review comparing the two approaches in adults found that laparoscopic patients left the hospital about one day sooner and returned to normal activity about five days earlier than those who had open surgery. In children, hospital stays were shorter by just under a day with the laparoscopic approach, though the difference in activity recovery was less clear.
In some cases of uncomplicated appendicitis, antibiotics alone can resolve the infection without surgery. This approach has gained traction in recent years, but there’s a catch: a significant percentage of people treated with antibiotics alone eventually develop appendicitis again and need surgery later.
What Recovery Looks Like
After a laparoscopic appendectomy, most people return to work within one to two weeks. Open surgery takes longer. For the first two weeks or so, you’ll need to avoid lifting anything heavy, including children, large grocery bags, pet food, or backpacks. Strenuous activities like jogging, cycling, weight lifting, and aerobic exercise are also off-limits for about the same period.
If your appendix ruptured before surgery, recovery takes longer. You may need a drain placed to remove lingering fluid, and a course of antibiotics that extends days beyond your hospital stay. Some people with a ruptured appendix spend several days in the hospital before going home, compared to one or two days for an uncomplicated case.
The appendix has no known essential function in adults. Removing it causes no changes to digestion or long-term health, so once you’ve healed from surgery, the issue is permanently resolved.