A sudden inflammation or swelling of the appendix is called appendicitis. The appendix is a tube-like structure that branches off where the large intestine (colon) begins. It's pencil-thin and normally about
4 inches (10 cm) long.
For many years, scientists were unsure of the function the appendix had in the body. Now we know it helps make immunoglobulins, substances that are part of the immune system. Immunoglobulins are made in many parts of the body. Thus, removing the appendix does not seem to result in problems with the immune system.
Appendicitis is rarely fatal these days, due to today's use of antibiotics and safe surgery. The condition affects 1 in 15 people and strikes men more than women. It hardly ever affects children under 3 years old. It occurs most commonly in people between 10 and 30 years of age.
Inflammation of the appendix is usually the result of blockage causing an infection. The appendix is open at one end where it connects to the large intestine. Appendicitis may occur when the appendix is blocked by hardened masses of feces or a foreign body in the intestine. This blockage can cause inflammation of the appendix directly and can encourage bacterial infection.
Blockage may also occur if lymph nodes in the appendix swell. Less common causes of blockage are vegetable and fruit seeds, stomach worms, and thickened barium from prior X-rays.
In seniors, appendicitis is occasionally caused by a tumor (cancer) of the colon.