Many of us experience stomachaches that come and go but if you have pain in the lower right side of your abdomen, it may be appendicitis.

Appendicitis can sometimes be confused with other abdominal pains, but if you experience pain and tenderness in the abdomen and have fever or nausea, consult a physician immediately, says Dr. James Maher, professor of surgery at the University of Iowa College of Medicine and director of gastrointestinal surgery at UI Hospitals and Clinics. "Getting medical care before the appendix ruptures is important," says Maher, who adds that a ruptured appendix can be fatal.

The appendix is a small, finger- or worm-shaped projection attached to part of the large intestine on your right side. It is believed the appendix had a specific purpose at some point in evolution, but we don't know what it is, Maher says.

The appendix becomes inflamed when apiece of stool lodges in it or when its lymph tissue -- the tissue that produces a fluid containing white blood cells --enlarges due to infections, especially viral ones. When this happens, the mucous that pours into the appendix becomes infected, causing the symptoms of appendicitis, he explains.

Pain around the navel is usually the earliest symptom. You'll probably have no appetite and may feel nauseated. As the infection progresses, the pain becomes more severe. You may feel feverish and the pain may move to the lower right part of the abdomen as inflammation spreads. Pain may subside briefly, then become generalized and very severe. If you don't seek treatment, the appendix may burst, spreading infected fluid into the abdomen.

There is no way to prevent appendicitis once it develops and surgery is the only treatment, Maher says. If the appendix is removed in the early stages of pain, you can be discharged from the hospital after a few days with little chance of serious complications. The risk of complications is greater from a ruptured appendix because infected fluid spreads into the abdomen. Your physician probably will prescribe medication following surgery. Recovery can take two to six weeks.

Appendicitis can affect people of all ages but is more difficult to diagnose in children under age four and in adults over 70. In these individuals the appendix may burst without causing the usual symptoms and so in these age groups, a ruptured appendix is more common, Maher says. The incidence of appendicitis is declining and now affects only six out of 100 people. Sometimes, if you request it, your surgeon can remove your appendix during another surgical procedure being conducted near the appendix, such as a hysterectomy. This is done only if it doesn't increase the risks associated with the original surgery, he adds.