Inflammation of the appendix, leading to severe abdominal pain

  • More common under the age of 40, especially among adolescents
  • Slightly more common in males
  • A low-fibre diet is a risk factor
  • Genetics is not a significant factor

Appendicitis is inflammation affecting the appendix, the small, blind-ended tube attached to the first section of the large intestine. The disorder is common, especially among adolescents, affecting about 1 in 500 people every year in the UK. Appendicitis is a common cause of sudden, severe pain in the abdomen, and removal of the appendix is one of the most commonly performed emergency operations. The disorder occurs most commonly in developed countries where the typical diet is low in fibre.

In most cases of appendicitis, no cause is detected, but in some instances the inflammation is the result of a blockage inside the appendix. Blockages sometimes occur when a lump of faecal material passes from the large intestine into the appendix and becomes lodged there. The closed end of the appendix beyond the obstruction then becomes infected with bacteria and inflamed.

What are the symptoms?

Symptoms differ from one person to another. The early symptoms usually develop over a few hours and include:

  • Sudden onset of intermittent pain that is first felt in the upper abdomen or around the navel.

  • Nausea, with or without vomiting.

Less often, there may be:

  • Diarrhoea.

  • Mild fever.

  • Loss of appetite.

  • Frequent passing of urine.

After a few hours, the pain shifts to the lower right abdomen. If treatment is delayed, the appendix may rupture, and intestinal matter containing a high concentration of bacteria can leak into the abdomen. The result may be peritonitis, a potentially serious condition in which the membrane that lines the abdominal cavity becomes inflamed. If the appendix ruptures, the pain becomes widespread and severe.

What might be done?

Your doctor will first ask you about the development of your symptoms. He or she will then examine your abdomen and may also insert a gloved finger into the rectum to determine whether there is tenderness in the area around the appendix. You may also have a blood test to measure the white blood cell count. An elevated white cell count may be a sign of inflammation. If your doctor suspects that you have appendicitis, you will be admitted to hospital immediately, where imaging with ultrasound scanning or CT scanning may confirm the diagnosis.

The usual treatment is removal of the appendix by minimally invasive surgery (see Endoscopic surgery) or by conventional open surgery. The operation is relatively simple and is performed under general anaesthesia. There are usually no long-term adverse effects following either type of operation, and recovery normally takes only 3–4 days.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

Back to top