Appendicitis
 National Digestive Diseases Information Clearinghouse 

U.S. Department 

of Health and 

Human Services 

NATIONAL 

INSTITUTES 

OF HEALTH 

What is appendicitis? 

Appendicitis is a painful swelling and infection of the appendix. 

What is the appendix? 

The appendix is a fingerlike pouch attached 

to the large intestine and located in the lower 

right area of the abdomen. Scientists are 

not sure what the appendix does, if anything, 

but removing it does not appear to affect a 

person’s health. The inside of the appendix 

is called the appendiceal lumen. Mucus 

created by the appendix travels through the 

appendiceal lumen and empties into the 

large intestine. 

What causes appendicitis? 

Obstruction of the appendiceal lumen causes 

appendicitis. Mucus backs up in the appendiceal lumen, causing bacteria that normally 

live inside the appendix to multiply. As a 

result, the appendix swells and becomes 

infected. Sources of obstruction include 

• 	 feces, parasites, or growths that clog the 

appendiceal lumen 

• 	 enlarged lymph tissue in the wall of the 

appendix, caused by infection in the 

gastrointestinal tract or elsewhere in 

the body 

• 	 inflammatory bowel disease, including 

Crohn’s disease and ulcerative colitis 

• 	 trauma to the abdomen 

Liver 

Small 

intestine 

Large 

intestine 

Stomach 

Anus Appendix 

The appendix is a fingerlike pouch attached to the 

large intestine in the lower right area of the abdomen. 

An inflamed appendix will likely burst if 

not removed. Bursting spreads infection 

throughout the abdomen—a potentially dangerous condition called peritonitis. 

Who gets appendicitis? 

Anyone can get appendicitis, but it is more 

common among people 10 to 30 years old. 

Appendicitis leads to more emergency 

abdominal surgeries than any other cause. 
What are the symptoms of 

appendicitis? 

Most people with appendicitis have classic 

symptoms that a doctor can easily identify. 

The main symptom of appendicitis is 

abdominal pain. 

The abdominal pain usually 

• 	 occurs suddenly, often causing a person 

to wake up at night 

• 	 occurs before other symptoms 

• 	 begins near the belly button and then 

moves lower and to the right 

• 	 is new and unlike any pain felt before 

• 	 gets worse in a matter of hours 

• 	 gets worse when moving around, taking 

deep breaths, coughing, or sneezing 

Other symptoms of appendicitis may include 

• 	 loss of appetite 

• 	 nausea 

• 	 vomiting 

• 	 constipation or diarrhea 

• 	 inability to pass gas 

• 	 a low-grade fever that follows other 


symptoms
 

• 	 abdominal swelling 

• 	 the feeling that passing stool will relieve 

discomfort 

Symptoms vary and can mimic other sources 

of abdominal pain, including 

• 	 intestinal obstruction 

• 	 inflammatory bowel disease 

• 	 pelvic inflammatory disease and other 

gynecological disorders 

• 	 intestinal adhesions 

• 	 constipation 

How is appendicitis 

diagnosed? 

A doctor or other health care provider can 

diagnose most cases of appendicitis by taking 

a person’s medical history and performing 

a physical examination. If a person shows 

classic symptoms, a doctor may suggest 

surgery right away to remove the appendix 

before it bursts. Doctors may use laboratory 

and imaging tests to confirm appendicitis if 

a person does not have classic symptoms. 

Tests may also help diagnose appendicitis in 

people who cannot adequately describe their 

symptoms, such as children or the mentally 

impaired. 

Medical History 

The doctor will ask specific questions about 

symptoms and health history. Answers 

to these questions will help rule out other 

conditions. The doctor will want to know 

when the pain began and its exact location 

and severity. Knowing when other symptoms 

appeared relative to the pain is also helpful. 

The doctor will ask questions about other 

medical conditions, previous illnesses and 

surgeries, and use of medications, alcohol, or 

illegal drugs. 

Physical Examination 

Details about the abdominal pain are key 

to diagnosing appendicitis. The doctor will 

assess pain by touching or applying pressure 

to specific areas of the abdomen. 

2 	 Appendicitis 
Responses that may indicate appendicitis 

include 

• 	 Guarding. Guarding occurs when a person subconsciously tenses the abdominal muscles during an examination. 

Voluntary guarding occurs the moment 

the doctor’s hand touches the abdomen. 

Involuntary guarding occurs before the 

doctor actually makes contact. 

• 	 Rebound tenderness. A doctor tests 

for rebound tenderness by applying 

hand pressure to a patient’s abdomen 

and then letting go. Pain felt upon 

the release of the pressure indicates 

rebound tenderness. A person may 

also experience rebound tenderness as 

pain when the abdomen is jarred—for 

example, when a person bumps into 

something or goes over a bump in a car. 

• 	 Rovsing’s sign. A doctor tests for Rovsing’s sign by applying hand pressure 

to the lower left side of the abdomen. 

Pain felt on the lower right side of the 

abdomen upon the release of pressure 

on the left side indicates the presence of 

Rovsing’s sign. 

• 	 Psoas sign. The right psoas muscle 

runs over the pelvis near the appendix. 

Flexing this muscle will cause abdominal pain if the appendix is inflamed. A 

doctor can check for the psoas sign by 

applying resistance to the right knee as 

the patient tries to lift the right thigh 

while lying down. 

• 	 Obturator sign. The right obturator 

muscle also runs near the appendix. 

A doctor tests for the obturator sign 

by asking the patient to lie down with 

the right leg bent at the knee. Moving 

the bent knee left and right requires 

flexing the obturator muscle and will 

cause abdominal pain if the appendix is 

inflamed. 

Women of childbearing age may be asked to 

undergo a pelvic exam to rule out gynecological conditions, which sometimes cause 

abdominal pain similar to appendicitis. 

The doctor may also examine the rectum, 

which can be tender from appendicitis. 

Laboratory Tests 

Blood tests are used to check for signs of 

infection, such as a high white blood cell 

count. Blood tests may also show dehydration or fluid and electrolyte imbalances. 

Urinalysis is used to rule out a urinary tract 

infection. Doctors may also order a pregnancy test for women. 

Imaging Tests 

Computerized tomography (CT) scans, which 

create cross-sectional images of the body, can 

help diagnose appendicitis and other sources 

of abdominal pain. Ultrasound is sometimes 

used to look for signs of appendicitis, especially in people who are thin or young. An 

abdominal x ray is rarely helpful in diagnosing appendicitis but can be used to look for 

other sources of abdominal pain. Women 

of childbearing age should have a pregnancy 

test before undergoing x rays or CT scanning. 

Both use radiation and can be harmful to a 

developing fetus. Ultrasound does not use 

radiation and is not harmful to a fetus. 

How is appendicitis treated? 

Surgery 

Typically, appendicitis is treated by removing 

the appendix. If appendicitis is suspected, a 

doctor will often suggest surgery without conducting extensive diagnostic testing. Prompt 

surgery decreases the likelihood the appendix will burst. 

3 	 Appendicitis 
Surgery to remove the appendix is called 

appendectomy and can be done two ways. 

The older method, called laparotomy, 

removes the appendix through a single 

incision in the lower right area of the abdomen. The newer method, called laparoscopic 

surgery, uses several smaller incisions and 

special surgical tools fed through the incisions to remove the appendix. Laparoscopic 

surgery leads to fewer complications, such as 

hospital-related infections, and has a shorter 

recovery time. 

Surgery occasionally reveals a normal 

appendix. In such cases, many surgeons will 

remove the healthy appendix to eliminate 

the future possibility of appendicitis. Occasionally, surgery reveals a different problem, 

which may also be corrected during surgery. 

Sometimes an abscess forms around a burst 

appendix—called an appendiceal abscess. 

An abscess is a pus-filled mass that results 

from the body’s attempt to keep an infection from spreading. An abscess may be 

addressed during surgery or, more commonly, drained before surgery. To drain 

an abscess, a tube is placed in the abscess 

through the abdominal wall. CT is used to 

help find the abscess. The drainage tube is 

left in place for about 2 weeks while antibiotics are given to treat infection. Six to 8 weeks 

later, when infection and infl ammation 

are under control, surgery is performed to 

remove what remains of the burst appendix. 

Nonsurgical Treatment 

Nonsurgical treatment may be used if surgery is not available, if a person is not well 

enough to undergo surgery, or if the diagnosis is unclear. Some research suggests that 

appendicitis can get better without surgery. 

Nonsurgical treatment includes antibiotics to 

treat infection and a liquid or soft diet until 

the infection subsides. A soft diet is low in 

fiber and easily breaks down in the gastrointestinal tract. 

Recovery 

With adequate care, most people recover 

from appendicitis and do not need to 

make changes to diet, exercise, or lifestyle. 

Full recovery from surgery takes about 4 to 

6 weeks. Limiting physical activity during 

this time allows tissues to heal. 

What should people do 

if they think they have 

appendicitis? 

Appendicitis is a medical emergency that 

requires immediate care. People who think 

they have appendicitis should see a doctor 

or go to the emergency room right away. 

Swift diagnosis and treatment reduce the 

chances the appendix will burst and improve 

recovery time. 

4 Appendicitis 
Points to Remember 

• 	 Appendicitis is a painful swelling and 

infection of the appendix. 

• 	 The appendix is a fi ngerlike pouch 


attached to the large intestine and 


located in the lower right area of the 


abdomen. 


• 	 Symptoms of appendicitis may include 

abdominal pain, loss of appetite, nausea, vomiting, constipation or diarrhea, 

inability to pass gas, low-grade fever, 

and abdominal swelling. 

• 	 A doctor can diagnose most cases of 

appendicitis by taking a person’s medical history and performing a physical 

examination. Sometimes laboratory and 

imaging tests are needed to confi rm the 

diagnosis. 

• 	 Appendicitis is typically treated by 


removing the appendix. 


• 	 Appendicitis is a medical emergency 


that requires immediate care.
 

Hope through Research 

The National Institute of Diabetes and 

Digestive and Kidney Diseases (NIDDK) 

conducts and supports basic and clinical 

research into many digestive disorders. 

Participants in clinical trials can play a more 

active role in their own health care, gain 

access to new research treatments before 

they are widely available, and help others 

by contributing to medical research. For 

information about current studies, visit 

www.ClinicalTrials.gov. 

For More Information 

American Academy of Family Physicians 

P.O. Box 11210 

Shawnee Mission, KS 66207–1210 

Phone: 1–800–274–2237 or 913–906–6000 

Email: fp@aafp.org 

Internet: www.aafp.org 

American College of Surgeons 

633 North Saint Clair Street 

Chicago, IL 60611–3211 

Phone: 1–800–621–4111 or 312–202–5000 

Fax: 312–202–5001 

Email: postmaster@facs.org 

Internet: www.facs.org 

American Society of Colon and Rectal 

Surgeons 

85 West Algonquin Road, Suite 550 

Arlington Heights, IL 60005 

Phone: 847–290–9184 

Fax: 847–290–9203 

Email: ascrs@fascrs.org 

Internet: www.fascrs.org 

You may also find additional information about this 

topic by 

• searching the NIDDK Reference Collection at 

www.catalog.niddk.nih.gov/resources

• visiting MedlinePlus at www.medlineplus.gov

This publication may contain information about medications. When prepared, this publication included 

the most current information available. For updates 

or for questions about any medications, contact 

the U.S. Food and Drug Administration toll-free at 

1–888–INFO–FDA (463–6332) or visit www.fda.gov. 

Consult your doctor for more information. 

5 	 Appendicitis 
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Phone: 1–800–891–5389
 

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Email: nddic@info.niddk.nih.gov
 

Internet: www.digestive.niddk.nih.gov
 

The National Digestive Diseases Information 

Clearinghouse (NDDIC) is a service of the 

National Institute of Diabetes and Digestive 

and Kidney Diseases (NIDDK). The NIDDK 

is part of the National Institutes of Health of 

the U.S. Department of Health and Human 

Services. Established in 1980, the Clearinghouse 

provides information about digestive diseases 

to people with digestive disorders and to their 

families, health care professionals, and the 

public. The NDDIC answers inquiries, develops 

and distributes publications, and works closely 

with professional and patient organizations and 

Government agencies to coordinate resources 

about digestive diseases. 

Publications produced by the Clearinghouse are 

carefully reviewed by both NIDDK scientists and 

outside experts. This publication was reviewed 

by Jason A. Brodsky, M.D., Shady Grove 

Adventist Hospital, Rockville, MD. 

This publication is not copyrighted. The Clearinghouse 

encourages users of this fact sheet to duplicate and 

distribute as many copies as desired. 

This fact sheet is also available at 

www.digestive.niddk.nih.gov. 

U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES 

National Institutes of Health 

NIH Publication No. 09–4547 

November 2008