What is Appendicitis?

Appendicitis is an inflammation of the appendix, a long, thin pouch attached to the colon on the right side of the abdomen. Although the appendix serves no known purpose, experts believe that at one time the organ may have played a role in digestion.

When the appendix becomes inflamed and then infected and fills with pus, it causes pain that begins near the navel and gradually moves to the lower right abdomen. Over time, this pain may become severe, and the appendix may rupture. This can lead to a life-threatening infection called peritonitis, and requires immediate medical attention.

Appendicitis can affect people of all ages, although it is more common between the ages of 10 and 30. It is rare in children younger than 1, and is most common in adolescents.

Although the exact cause of appendicitis is not always known, it appears that several different factors can trigger the condition. Infection in the digestive tract may allow bacteria to invade the appendix, leading to inflammation and the formation of pus (infection). In some cases, food waste or a hard piece of stool (called a fecal stone or fecolith) can become lodged in the entrance to the appendix or inside the cavity (lumen) that runs its length. This fecolith may be seen on an abdominal x-ray.

In rare cases, a traumatic injury to the abdomen can trigger appendicitis. Genetics may also play a role, as appendicitis sometimes runs in families. This may be the result of a genetic factor that leaves a person more vulnerable to obstruction of the appendix.

Surgical removal of the appendix (appendectomy) is the standard treatment for appendicitis and is the most common emergency surgical procedure of the abdomen, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

In most cases, surgery can provide quick and effective treatment of appendicitis with few complications. However, it is important to treat this condition promptly to prevent infections, such as peritonitis. In rare cases, appendicitis may be fatal.

Notify your physician if

  • You or a family member has symptoms of appendicitis.
  • The following occur while surgery is pending or after surgery:
    • Fever of 102°F (38.9° C) or over.
    • Continued vomiting.
    • Increased pain in the abdomen.
    • Fainting.
    • Blood in the stool or vomit.
    • Dizziness or headache.

Signs and symptoms of appendicitis

Appendicitis frequently begins as an ache around the navel (belly button) that gradually shifts to the lower right abdomen. The pain may become worse as the inflammation spreads to the tissues surrounding the abdomen, such as the peritoneum, or inner lining of the abdomen.

In many cases, the pain eventually settles in an area of the body known as McBurney point, which is halfway between the navel and the top of the right pelvic bone. However, the exact location of the pain will depend on the location of the person’s appendix, which can vary. Wherever the pain settles, the region tends to feel tender when even gentle pressure is applied. If this pressure is released quickly, the pain may worsen. This condition is known as rebound tenderness. Coughing, sneezing, walking, taking deep breaths or performing other jarring movements can also worsen the pain, especially if the appendix is touching the peritoneum.

Other symptoms that may occur with appendicitis include:

  • Nausea and vomiting
  • Loss of appetite
  • Low-grade fever
  • Constipation
  • Inability to pass gas
  • Diarrhea
  • Abdominal swelling
  • Frequent need to urinate

Appendicitis that is not treated promptly may result in a rupture of the appendix. Initially, this perforation may cause the patient to feel better as the pressure is released. However, a burst appendix allows infectious organisms and the contents of the intestines to rush into the peritoneal cavity. This can cause an extremely dangerous infection of the abdominal-cavity lining known as peritonitis.

If the cavity becomes infected, the patient’s abdomen may become distended with gas and fluid and will likely feel tight, hard and tender to the touch. Widespread abdominal pain (unlike the localized pain of appendicitis) may result, and the patient may find it impossible to pass gas or have a bowel movement. Worsening pain and fever, excessive thirst, and reduced urine output are also associated with peritonitis. Young children with peritonitis may become disoriented or lose consciousness and pass out if they are not treated promptly. Peritonitis is an emergency situation that requires immediate medical care.

The combination of infection and released intestinal contents can also form an abscess, a walled-off area of infection outside the intestine. Such abscesses may range in size from a walnut to a grapefruit, and are usually removed surgically.

Ruptures can also infect a woman’s ovaries and fallopian tubes, causing infertility. If bacteria from a rupture enter the bloodstream, a life-threatening condition called sepsis may result.

Although many patients experience symptoms commonly associated with appendicitis, others do not. Women who are pregnant often do not experience classic symptoms of appendicitis because of the changes an expanding uterus causes in the abdominal cavity. Therefore, pregnant women should consult a physician if they experience pain on the right side of the abdomen, particularly during their third trimester. Elderly patients also are less likely to experience fever or severe abdominal pain than younger adults. As a result, they should contact a physician if they have even slight fever and abdominal pain on their right side.

In addition, people with certain conditions may not feel symptoms and may instead experience a general feeling of sickness. Such conditions include obesity, cancer, diabetes and HIV infection. People who are undergoing immunosuppressive therapy or who have received a transplanted organ also may not experience specific symptoms.

Children younger than 2 may experience typical symptoms of appendicitis, but cannot always communicate the pain they are feeling. In addition, children may have widespread abdominal pain rather than the typical pain specific to the appendix. Instead, parents should carefully monitor and seek medical attention for children who appear irritable or lethargic.

Diagnosis methods for appendicitis

Appendicitis is often difficult to detect, particularly in children. However, it is crucial to diagnose the condition early. Once an appendix has ruptured and peritonitis has set in, the condition can be very difficult to treat. Children are more likely than adults to suffer a ruptured appendix. For this reason, parents should consult a physician anytime their child has a stomach ache that appears to be serious or unusual.

A physician will perform a complete physical examination and compile a thorough medical history. The physician will pay special attention to the abdomen, applying gentle pressure and quickly releasing it to see if the pain worsens, indicating an inflamed peritoneum. Signs of appendicitis include abdominal rigidity and a patient’s instinct to tense the abdominal muscles when pressure is applied, a response known as “guarding.” Other potential signs are pain when the patient lies on the left side and extends the right leg and pain when the right hip is rotated toward the center of the body.

The patient’s blood may also be tested to check for an elevated white cell count, which indicates the presence of an infection. A urine test can also help detect other conditions that might cause similar symptoms, such as a kidney stone (solid mass of tiny crystals that causes pain when it moves down the ureter) or urinary tract infection.

Imaging tests can help confirm the presence of appendicitis or another disease. An abdominal x-ray can reveal signs of obstruction, foreign bodies, perforation or a fecolith. An ultrasound scan(which uses high-frequency sound waves to create an image) can show inflammation of the appendix or reveal an ectopic pregnancy (pregnancy that occurs outside the uterus) or gallbladder disease. A computed axial tomography (CAT) scan (which uses a series of computer-generated x-rays to form a detailed image) is the most frequently used imaging test because it provides the most detailed and comprehensive look at the abdomen. Women of childbearing age will usually be given a pregnancy test before undergoing an x-ray procedure.

Pregnant women will typically be given an ultrasound examination as x-ray procedures may be harmful to a developing fetus. However, recent research shows that magnetic resonance imaging (MRI) may be safer and more effective than ultrasound in diagnosing appendicitis in this population.

In some cases, symptoms that appear to indicate appendicitis may actually indicate another disorder. These may include:

Various digestive disorders

Many such disorders sometimes mimic the symptoms of appendicitis. These disorders include Crohn's disease (inflammation of the digestive tract), gastroenteritis (inflammation of the stomach and intestinal linings), Meckel's diverticulum (birth defect in which a small sac is present in the ileum), diverticulitis (infection or irritation of the diverticula) or intussusception (disorder in which blockage of the intestine occurs).

Ectopic pregnancy

A pregnancy that occurs outside the uterus can cause pain similar to that associated with appendicitis.

Ovarian cysts

A cyst that develops on the right ovary may mimic symptoms of appendicitis.

Pelvic inflammatory disease (PID)

Infection of a woman’s internal reproductive organs, which may be caused by sexually transmitted diseases. Pain associated with PID may closely resemble symptoms of appendicitis.

Kidney stone

A stone from the right kidney may become stuck in the ureter, the long tube that runs from the kidney to the bladder. This can cause pain similar to that of appendicitis.

Urinary tract infection

An infection that can occur along any part of the urinary tract (e.g., kidneys, ureters, bladder, urethra) and cause pain similar to that of appendicitis.

Other diseases

Other illnesses that may cause abdominal pain include pneumonia and heart disease.

Treatment options for appendicitis

Appendicitis cannot be prevented, but it can be treated. In instances where appendicitis is treated early, patients are given fluids intravenously prior to surgery in order to prevent dehydration and maintain normal electrolyte levels. Antibiotics may also be given to slow the spread of infection. Rarely, the body is successful in containing the appendicitis without surgical treatment if the infection and inflammation do not spread to other parts of the abdominal area. Patients should seek evaluation and treatment immediately if they suspect that they may have appendicitis.

Conversely, patients who seek medical attention within the first 24 to 72 hours after painful symptoms appear typically undergo immediate appendectomy. This procedure is the standard treatment for appendicitis and involves removal of the appendix through traditional open surgery or laparoscopic surgery.

Laparoscopic surgery requires just a few small incisions into the abdomen. A thin tube called a laparoscope is inserted into one of the incisions through a hollow instrument called a cannula. The laparoscope has an attached camera and light that provide a magnified view of the interior of the abdomen. A surgeon watches the image on a monitor and inserts instruments into the other incisions to remove the appendix with minimum scarring.

However, traditional surgery will likely be necessary if the appendix has ruptured or an abscess is present. A larger incision is necessary in traditional surgery, during which the surgeon may wash out the abdomen with fluid. Temporary drains may be necessary. Traditional surgery usually requires intravenous (I.V.) antibiotics, a hospital stay and a longer recovery period (two to three days on average) than laparoscopic surgery (less than one day).

In a small minority of cases, the surgeon may discover during the procedure that the appendix is in fact normal and healthy. In such cases, the appendix may still be removed to prevent any future episodes of appendicitis, and the surgeon will likely look for other potential abdominal causes of the patient’s symptoms.

Antibiotic therapy may be administered immediately following surgery to reduce the chance of infection. Patients who have traditional surgery may have to limit strenuous activity for four to six weeks following the procedure. Recovery time is usually shorter for those who have laparoscopic surgery. Most patients make a quick and full recovery and do not require any alterations to lifestyle or diet.

In rare cases, people who have undergone an appendectomy can experience “stump appendicitis,” inflammation of the tiny part of the appendix that remains after surgery. In such cases, a second surgery may be needed to remove the remainder of the appendix. Leaving a stump less than 3 millimeters long in the original surgery may prevent stump appendicitis.

Additional Information


  • Don't take any laxatives, enemas or medicines for pain. Laxatives may cause rupture, and pain or fever reducers make diagnosis more difficult.
  • Pain medicine will be prescribed after surgery.
  • Antibiotics if infection is present.
  • Stool softeners to prevent constipation may be recommended.


  • Rest in a bed or chair until surgery.
  • Resume normal activities gradually after surgery.


  • Don't eat or drink anything until appendicitis has been diagnosed. Anesthesia for surgery is much safer if the stomach is empty. If you are very thirsty, wash your mouth out with water.
  • A liquid diet, progressing to soft diet following surgery.