The symptoms are different from person to person but may include abdominal pain, usually starting near the bellybutton, then moving to the right lower side of the belly; loss of appetite; nausea & vomiting; constipation or diarrhea; trouble passing gas; and a mild fever.

The symptoms of peritonitis are much more severe. The pain is worse and is felt throughout the abdomen. The abdomen may be swollen and feel tight or hard.

People under 10 or over 50 years old, as well as pregnant women, are less likely to have the usual symptoms of appendicitis. Because of this, they may not get treatment right away, which makes it more likely that their appendix will burst. It is very important for these people to be especially careful to report the early signs of appendicitis.