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
Diagnosis and Tests
- Abdominal and Pelvic CT (Radiological Society of North America, American College of Radiology) Also in Spanish
- Abdominal exploration - slideshow (Medical Encyclopedia) Also in Spanish
- Abdominal Pain (Stomach Pain), Short-Term (American Academy of Family Physicians) Also in Spanish
- Abdominal Ultrasound (Radiological Society of North America, American College of Radiology) Also in Spanish
Health Check Tools
- Abdominal Pain (DSHI Systems)
- ClinicalTrials.gov: Appendicitis (National Institutes of Health)
Journal ArticlesReferences and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Appendicitis (Nemours Foundation)
- Appendicitis (For Parents) (Nemours Foundation) Also in Spanish
- Children's (Pediatric) Abdominal Ultrasound Imaging (Radiological Society of North America, American College of Radiology) Also in Spanish
- Ultrasound: Abdomen (For Parents) (Nemours Foundation) Also in Spanish