Appendicitis

Definition

Appendicitis is a condition in which your appendix becomes inflamed and filled with pus. Your appendix is a finger-shaped pouch that projects out from your colon on the lower right side of your abdomen. This small structure has no known essential purpose, but that doesn’t mean it can’t cause problems.

The main symptom of appendicitis is pain that typically begins around your navel and then shifts to your lower right abdomen. The pain of appendicitis usually increases over a period of six to 12 hours, and eventually may become very severe.

Anyone can develop appendicitis, but it most often strikes people between the ages of 10 and 30. The standard treatment for appendicitis is surgical removal of the appendix.

Symptoms


Appendicitis can cause a variety of symptoms that may change over time:

  • Early on, the most common symptom is an aching pain around your navel that often shifts later to your lower right abdomen.
  • As the inflammation spreads to nearby tissues, the pain may become sharper and more severe.
  • Eventually, the pain tends to settle in your lower right abdomen — near your appendix at what’s known as McBurney point. This point is about halfway between your navel and the top of your right pelvic bone.

But the location of your pain may vary, depending on your age and the position of your appendix. Young children or pregnant women, especially, may have appendicitis pain in different places.

What makes pain worse
If you apply gentle pressure to the area that hurts, it will feel tender. As you release the pressure, especially if you do it suddenly, appendicitis pain often will feel worse (rebound tenderness). It will also tend to get worse if you cough, walk or make other jarring movements. This is particularly true if the inflamed appendix is touching the peritoneum — the silk-like membrane that lines the inner abdominal wall and enfolds the intestines. The pain may lessen somewhat if you lie on your side and pull your knees up toward your chest.

Symptoms other than pain
In addition to pain, you may have one or more of the following appendicitis symptoms:

  • Nausea and sometimes vomiting
  • Loss of appetite
  • A low-grade fever that starts after other symptoms appear
  • Constipation
  • An inability to pass gas
  • Diarrhea
  • Abdominal swelling

Causes

The cause of appendicitis is not always clear. Sometimes it’s the result of:

  • An obstruction. Food waste or a hard piece of stool (fecal stone) can become trapped in an orifice of the cavity that runs the length of your appendix.
  • An infection. Appendicitis may also follow an infection, such as a gastrointestinal viral infection, or it may result from other types of inflammation.

In both cases, bacteria may subsequently invade rapidly, causing the appendix to become inflamed and filled with pus. If not treated promptly, your appendix is likely to rupture.

When to seek medical advice

Children are more likely to have a ruptured appendix than adults are. Children don’t always have typical symptoms of appendicitis, and parents may delay getting treatment. For that reason, it’s best not to take abdominal pain lightly. Even if you suspect a “stomachache” isn’t serious, call your doctor just to make sure.

Older adults also have a higher incidence of ruptured appendix, possibly because of delay in seeing a doctor for abdominal pain.

Tests and diagnosis

The pain from appendicitis may change over time, so establishing a diagnosis can sometimes be difficult. In addition, abdominal pain can arise from a number of health problems other than appendicitis. Other conditions with abdominal pain that may resemble that of appendicitis include:

  • Ectopic pregnancy. An ectopic pregnancy — one that occurs outside the lining of the uterus — can cause similar pain.
  • Certain ovarian cysts. A right-sided ovarian cyst may produce pain in the same general area as appendicitis.
  • Kidney stone. Occasionally, a stone from the right kidney will pass into the ureter, which runs from the kidney to the bladder, and get stuck there. This causes considerable pain that may mimic appendicitis, especially in adults.
  • Crohn’s disease. This condition, which causes chronic inflammation of the digestive tract, also can mimic appendicitis.

Making a diagnosis
To help diagnose appendicitis, your doctor will likely take a history of your signs and symptoms and perform a thorough examination of your abdomen. When gentle pressure on the painful area is suddenly released, appendicitis pain will often feel worse if the adjacent peritoneum is inflamed. Other signs your doctor may watch for include abdominal rigidity and a tendency to stiffen your abdominal muscles in response to pressure over the inflamed appendix (guarding).

In addition, your doctor may recommend the following procedures:

  • Blood test. This allows your doctor to check for a high white blood cell count, which may indicate an infection.
  • Urine test. Your doctor may want you to have a urinalysis to make sure that a urinary tract infection or a kidney stone isn’t causing your pain. If it is a kidney stone, red blood cells are usually seen during microscopic examination of the urine.
  • Imaging tests. Your doctor may also recommend an abdominal X-ray or ultrasound scan to help confirm appendicitis or find other causes for your pain. An ultrasound scan uses high-frequency sound waves and computer technology to provide images of your internal organs.

More commonly, a computerized tomography (CT) scan is used for confirming a diagnosis. A CT scan is an imaging test that uses a series of computer-generated X-rays to provide a more comprehensive view of your internal organs than conventional X-rays do. It can also help reveal other potential diagnoses if your appendix is not the source of your pain. Because a CT scan produces radiation, women of childbearing age need to have a pregnancy test before proceeding with the scan.

Complications

The most serious complication of appendicitis is if your appendix ruptures (perforates) and the contents of your intestines and infectious organisms invade the abdominal cavity. This can cause an infection of the lining of the cavity (peritonitis).

When your appendix ruptures, you may suddenly feel better. But soon afterward, your entire abdomen may become distended with gas and fluid and will likely feel tight, hard and tender to the touch. You’ll also have pain throughout your abdomen, but may not have the severe, localized pain of appendicitis. In addition, you may not be able to pass gas or have a bowel movement because of the inflammation. Other signs and symptoms may include a fever, thirst and a low urine output.

Peritonitis is a medical emergency. If you or a family member develops signs of this abdominal infection, go to an emergency room immediately. Even with prompt treatment, peritonitis can be extremely serious.

Sometimes, infection and the seepage of intestinal contents may form an abscess, a walled-off area of infection (appendiceal abscess). The abscess may be as small as a walnut or as large as a grapefruit. Regardless of its size, it requires treatment before the abscess itself perforates, causing peritonitis.