Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 13, 2016

Appendicitis is a health condition in which the appendix can become inflamed, swollen and filled with pus. It is the most common cause of acute abdominal pain that requires surgical intervention in the United States. If left untreated, appendicitis can lead to an appendiceal abscess or peritonitis, which is an infection that can be life threatening.


Definition & Facts

The appendix is the small pouch which is shaped like a finger and is approximately four inches long. It is typically situated on the lower-right side of the abdomen and opens into the large intestine.

In the course of a lifetime, one in every 15 people will develop appendicitis. The highest incidence is among males between the ages of 10 to 14, and females between the ages of 15 to 19.

Appendicitis typically involves the emergency consultation of a physician and evaluation in a hospital's emergency department. All cases of appendicitis are treated as a medical emergency requiring surgery, because even a less urgent situation such as an abscessed appendix cannot be identified without surgery. It is the most common abdominal emergency among children and young adults.

Symptoms & Complaints

The most common symptom of appendicitis is the presence of pain in the abdomen. The pain may have one or more of the following characteristics:

  • Begins near the belly button and then moves to the lower-right side of the abdomen
  • Worsens in a matter of hours
  • Worsens upon movement, taking deep breaths, coughing, or sneezing
  • Severe pain that many describe as being different from any pain previously experienced
  • Occurs suddenly and may awaken an individual from sleep

Other symptoms that may be present with appendicitis include nausea, vomiting, loss of appetite and constipation or diarrhea. An individual may also experience the inability to pass gas, abdominal distension, a low-grade fever, and the feeling that discomfort could be relieved by having a bowel movement.

If the swollen appendix is near the bladder or urinary tract, individuals may experience an inability to urinate, pain on urination or the frequent urge to urinate. If the appendix ruptures, the abdominal pain becomes even more severe and involves the entire abdominal area and is typically accompanied by a very high fever.

The most common symptoms seen in children younger than two years of age are vomiting and a swollen or bloated abdomen. Symptoms of fatigue and difficulty eating may be noted in toddlers with appendicitis.


Appendicitis is typically caused by a blockage of the lumen, which is the inside of the appendix. Commonly, the lumen becomes blocked by fecal material, however, the lumen can also become blocked by parasites or other growths.

The mucosal lining of the appendix and intestines is protected by lymphoid tissue to help fight viral infections and bacterial infections. In a condition called lymphoid hyperplasia, this tissue can swell and lead to the obstruction of the appendix.

Appendicitis can also be the result of obstruction by foreign bodies, such as intrauterine devices or other items swallowed; as well as tumors, ovarian cysts such as endometriomas, traumatic abdominal injuries, infections of the gastrointestinal tract and inflammatory bowel disease.

Diagnosis & Tests

Diagnosing appendicitis is an involved process as appendicitis symptoms may be vague or similar to other medical conditions, including urinary tract infections or bladder infections, gallbladder problems, Crohn's disease, intestinal infection, gastritis and ovary problems. Also, half of all individuals who present with appendicitis report atypical symptoms, such as pain located in different parts of the body.

A thorough medical history is taken by health care professionals which consists of specific questions about an individual's symptoms to help rule out other health conditions and can include when the abdominal pain began, the severity and location of an individual's pain, if and when other symptoms presented, present medical conditions, previous illnesses and past surgical procedures. Typically, the following tests are used to make a diagnosis of appendicitis:

Treatment & Therapy

An appendectomy, which is a surgery to remove the appendix, is the standard treatment for individuals with appendicitis. As severe complications can arise in the event of a ruptured appendix, doctors tend to quickly remove the appendix to err on the side of safety.

If an abscess has formed on the appendix, two procedures may be required for treatment. These include one procedure to drain the fluid and pus of the abscess, and a second procedure to remove the appendix. To prevent complications such as infection caused by peritonitis, antibiotics are typically administered prior to an appendectomy.

Surgeons can perform the surgery using one of the following methods:

If surgeons are able to perform an appendectomy prior to the perforation of the appendix, the typical hospital stay is two to three days. In cases where the appendix has perforated and complications arise such as peritonitis, a hospital stay may last up to a week to ensure adequate treatment.

Prevention & Prophylaxis

In general, appendicitis is not a condition that can be prevented. However, it is noted that the incidence of appendicitis is lower in cultures where individuals consume more daily dietary fiber. This is thought to decrease bowel transit time, decrease the viscosity of feces, and discourage the formation of fecaliths. A fecalith is a hard, stony mass of feces in the intestinal tract, which can lead to the obstruction of the appendix, resulting in appendicitis.