The appendix is a small, tube-like organ attached to the first part of the large intestine. It is located in the lower right part of the abdomen. It has no known function. A blockage inside of the appendix causes appendicitis. The blockage leads to increased pressure, problems with blood flow, and inflammation. If the blockage is not treated, the appendix can burst and spread infection into the abdomen. This causes a condition called peritonitis.
The main symptom is pain in the abdomen, often on the right side. It is usually sudden and gets worse over time. Other symptoms may include
Swelling in the abdomen
Loss of appetite
Nausea and vomiting
Constipation or diarrhea
Inability to pass gas
Low fever
Not everyone with appendicitis has all these symptoms.
Appendicitis is a medical emergency. Treatment almost always involves removing the appendix. Anyone can get appendicitis, but it is more common among people 10 to 30 years old.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
