Appendicitis is a painful medical condition where your appendix becomes infected and swollen. The appendix is a small, finger-shaped pouch attached to your large intestine on the lower right side of your belly. When it gets blocked and fills with bacteria, it becomes inflamed and infected, causing sharp pain that usually starts near your belly button and then moves to the lower right side.

Appendicitis is serious because an infected appendix can burst if not treated quickly, spreading infection through your abdomen. That's why people with appendicitis often need surgery to remove the appendix. The surgery is called an appendectomy, and it's one of the most common emergency operations doctors perform.

Symptoms include severe stomach pain, fever, nausea, and loss of appetite. Doctors can diagnose appendicitis with exams and scans, and while surgery might sound scary, it's usually straightforward and people recover quickly.

Interestingly, doctors still aren't completely sure what the appendix does, though it may help the immune system. What is clear is that people live perfectly normal, healthy lives after having their appendix removed.