Appendicitis is inflammation of the appendix, causing increasingly severe abdominal pain and other symptoms. Urgent surgery is required to avert the risk of severe complications caused by the appendix rupturing.
The appendix is a small, hollow, finger-like tube that extends from the beginning of the large bowel on the lower right hand side of the abdomen.
It has no known useful function. It is not always known what causes appendicitis but the obstruction of the appendix e.g: with faeces, is one possible cause. The blockage may result in a bacterial infection, causing the appendix to become inflamed and swollen.
Appendicitis occurs more commonly in males than females and most commonly occurs in children and adolescents. It is rare in infants. Appendicitis occurs less commonly in people who eat foods high in fibre and roughage, such as raw fruit and vegetables.
The most common early sign of appendicitis is sudden pain around the tummy button, in the middle of the abdomen. The pain becomes progressively more severe and moves to the lower right side of the abdomen. The pain may be worse with movement.
Other symptoms that may be experienced include:
- Loss of appetite
- Constipation or diarrhoea
- Low-grade fever
- Pain on pressing the abdomen.
If appendicitis is suspected it is important that urgent medical attention is sought so that an accurate diagnosis can be made and appropriate treatment given. This is especially true with children, in whom appendicitis can deteriorate quickly.
A diagnosis of appendicitis can usually be made based on a description of the symptoms and a physical examination.
In some instances, tests may be used to assist with diagnosis, including:
- Urine tests (to rule out urinary tract infection and kidney stones)
- Blood tests - an increased white blood cell count can indicate the presence of infection
- Abdominal x-ray, ultrasound scan, CT scan or MRI can help to confirm appendicitis or reveal other causes of abdominal pain.
Because urgent treatment is vital but appendicitis can sometimes be difficult to diagnose (notably in younger children) some surgically removed appendixes are found to be healthy.
Complications of appendicitis
Appendicitis is a potentially serious condition; it is important to remove an inflamed appendix before it ruptures. The time between the onset of pain and rupture can sometimes be only a matter of hours, especially in small children and infants.
If an inflamed appendix does rupture this can cause infection to spread into the abdomen and result in peritonitis - an inflammation of the peritoneum, the membrane that covers the abdominal organs. Peritonitis can be life-threatening and requires immediate surgery to remove the appendix and clean the abdominal cavity.
Surgical removal of the appendix (appendectomy) is the treatment of choice for appendicitis. Antibiotics alone are rarely used as a cure. An appendectomy is carried out under general anaesthetic using either open or keyhole (laparoscopic) surgery.
The traditional surgical technique for removing an inflamed appendix involves making an incision in the lower right side of the abdomen. The muscle layers are separated and the appendix is located and removed.
This "keyhole" surgical technique involves making three small incisions in the abdomen, and inserting a laparoscope (a fine narrow tube with a small camera at its tip) through one incision and surgical instruments through the other incisions. The laparoscope allows the surgeon to see the inside of the abdominal cavity on a television screen.
Antibiotics are usually given before and/or during surgery and may also be given after surgery. The antibiotics may be taken orally as liquid or tablets, or intravenously through a drip in the hand or arm (especially if the appendix has ruptured or peritonitis has developed).
Recovery times after surgery will vary according to the severity of the appendicitis and the surgical technique used. Laparoscopic appendectomy tends to have a faster recovery time. Fluids will be given intravenously until the bowel is working effectively.
Most people are able to be discharged home 1-4 days after their appendix has been removed but a longer hospital stay may be required if the appendix has ruptured or peritonitis has developed.
Kidshealth (2017). Appendicitis (Web Page). Paediatric Society of New Zealand (Wellington) and Starship Foundation (Auckland). https://www.kidshealth.org.nz/appendicitis [Accessed: 15/01/20]
Mayo Clinic (2019). Appendicitis (Web Page). Rochester, MN: Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/appendicitis/symptoms-causes/syc-20369543 [Accessed: 15/01/20]
NHS (2019). Appendicitis (Web Page). Redditch: National Health Service (NHS)
England. https://www.nhs.uk/conditions/appendicitis/ [Accessed: 15/01/20]
O’Toole, M.T. (Ed.) (2017). Appendicitis. Mosby’s Dictionary of Medicine, Nursing & Health Professions (10th ed.). St Louis, MI: Elsevier.Toprak, H. et al. (2018). Mimics of acute appendicitis – alternative diagnoses at sonography, CT, and MRI; specific imaging findings that can help in differential diagnosis. Clin Imaging 2018;48:90-105.
Last reviewed – January 2020
Go to our Medical Library Index Page to find information on other medical conditions.