Often a blockage inside the appendix causes the appendix to become inflamed and infected.
Abdominal pain, nausea, and fever are common.
Exploratory surgery or an imaging test, such as computed tomography or ultrasonography, is done.
Treatment involves surgery to remove the appendix and antibiotics to treat the infection.
(See also Acute Abdominal Pain Overview of Gastrointestinal Emergencies Certain gastrointestinal disorders can be life threatening and require emergency treatment. For many people, emergency treatment involves surgery. Abdominal pain, often severe, usually accompanies... read more .)
The appendix is a small finger-shaped tube projecting from the large intestine near the point where it joins the small intestine. The appendix may have some immune function, but it is not an essential organ.
Appendicitis is the most common cause of sudden, severe abdominal pain and abdominal surgery in the United States. Over 5% of the population develops appendicitis at some point. Appendicitis most commonly occurs during adolescence and in the 20s but may occur at any age.
The cause of appendicitis is not fully understood. However, in most cases, a blockage inside the appendix probably starts a process. The blockage may be from a small, hard piece of stool (fecalith), a foreign body, or, rarely, even worms. As a result of the blockage, the appendix becomes inflamed and infected. If inflammation continues without treatment, the appendix can rupture. A ruptured appendix may cause a pus-filled pocket of infection (abscess Abdominal Abscesses An abscess is a pocket of pus, usually caused by a bacterial infection. Most people have constant abdominal pain and a fever. Computed tomography or another imaging test can distinguish an abscess... read more ) to form. As a result, peritonitis Peritonitis Abdominal pain is common and often minor. Severe abdominal pain that comes on quickly, however, almost always indicates a significant problem. The pain may be the only sign of the need for surgery... read more (inflammation and usually infection of the abdominal cavity, which may result in a life-threatening infection) may develop. In a woman, the ovaries and fallopian tubes may become infected, and the resulting scarring may block the fallopian tubes and cause infertility. A ruptured appendix also may allow bacteria to infect the bloodstream—a life-threatening condition called sepsis Sepsis and Septic Shock Sepsis is a serious bodywide response to bacteremia or another infection plus malfunction or failure of an essential system in the body. Septic shock is life-threatening low blood pressure ... read more .
Fewer than 50% of people with appendicitis have the traditionally described symptoms in which pain begins in the upper abdomen or around the navel, then nausea and vomiting develop, and then, after a few hours, the nausea passes, and the pain shifts to the right lower portion of the abdomen. When a doctor presses on this area, it is tender, and when the pressure is released, the pain may increase sharply (rebound tenderness). A fever of 100° to 101° F (37.7° to 38.3° C) is common. Moving and coughing increase the pain.
In many people, particularly infants and children, the pain may be widespread rather than confined to the right lower portion of the abdomen. In older people and in pregnant women, the pain may be less severe, and the area is less tender.
If the appendix ruptures, pain may lessen for several hours. Then, peritonitis occurs, and pain and fever may become severe. Worsening infection can lead to shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more .
A doctor may suspect appendicitis after reviewing the person’s symptoms and examining the abdomen. Typically, surgery is done immediately if the doctor strongly suspects appendicitis.
If the diagnosis of appendicitis is not clear, doctors usually do an imaging test such as computed tomography Computed Tomography and Magnetic Resonance Imaging of the Digestive Tract Computed tomography (CT—see also Computed Tomography (CT)) and magnetic resonance imaging (MRI—see also Magnetic Resonance Imaging (MRI)) scans are good tools for assessing the size and location... read more (CT) or ultrasonography Ultrasound Scanning (Ultrasonography) of the Abdomen Ultrasound scanning uses sound waves to produce pictures of internal organs (see also Ultrasonography). An ultrasound scan can show the size and shape of many organs, such as the liver and pancreas... read more . Ultrasonography is particularly useful in children, in whom it is important to limit radiation exposure to reduce the risk of future cancers.
Surgeons can also do laparoscopy Laparoscopy Laparoscopy is an examination of the abdominal cavity using a fiberoptic instrument inserted through the abdominal wall. This is a surgical procedure done in an operating room. People are given... read more to explore the abdominal cavity and help determine the diagnosis.
A blood test often shows a moderate increase in the white blood cell count because of the infection, but there is no definitive blood test for appendicitis.
With an early operation, the chance of death from appendicitis is very low. The person can usually leave the hospital in 1 to 3 days, and recovery is normally quick and complete. However, older people often take longer to recover.
Without surgery or antibiotics (as might occur in a person in a remote location without access to modern medical care), more than 50% of people with appendicitis die.
For a ruptured appendix, the prognosis is more serious. Decades ago, a rupture was often fatal. Surgery and antibiotics have lowered the death rate to nearly zero, but repeated operations and a long recovery may be necessary.
Surgery is the main treatment of appendicitis. Delaying surgery until the cause of the abdominal pain is certain can be fatal: An infected appendix can rupture less than 36 hours after symptoms begin.
If appendicitis is found, fluids and antibiotics are given by vein and the appendix is removed (appendectomy). If the doctor does an operation and appendicitis is not found, the appendix is usually removed anyway to prevent any future risk of appendicitis.
There has been recent interest in treating appendicitis only with antibiotics, so that surgery can be postponed or avoided. Although this treatment may be successful in some people, it is still being studied, and surgical removal of the appendix is still considered the most effective and thus usually the recommended treatment for appendicitis.