The appendix is a small, tube-like structure

attached to the first part of the large intestine, also called the colon. The appendix

is located in the lower right portion of

the abdomen. It has no known function.

Removal of the appendix appears to cause

no change in digestive function.

Appendicitis is an inflammation of the

appendix. Once it starts, there is no effective medical therapy, so appendicitis is

considered a medical emergency. When

treated promptly, most patients recover

without difficulty. If treatment is delayed,

the appendix can burst, causing infection

and even death. Appendicitis is the most

common acute surgical emergency of the

abdomen. Anyone can get appendicitis,

but it occurs most often between the ages

of 10 and 30.

Causes

The cause of appendicitis relates to blockage of the inside of the appendix, known

as the lumen. The blockage leads to

increased pressure, impaired blood flow,

and inflammation. If the blockage is not

treated, gangrene and rupture (breaking

or tearing) of the appendix can result. 

Most commonly, feces blocks the inside

of the appendix. Also, bacterial or viral

infections in the digestive tract can lead to

National Digestive Diseases Information Clearinghouse

National

Institute of

Diabetes and

Digestive 

and Kidney

Diseases

NATIONAL 

INSTITUTES

OF HEALTH

Appendicitis

U.S. Department

of Health and

Human Services

The appendix is a small, tube-like structure attached to the first part of the large intestine, also called the colon. The

appendix is located in the lower right portion of the abdomen, near where the small intestine attaches to the large

intestine.
swelling of lymph nodes, which squeeze

the appendix and cause obstruction. This

swelling of lymph nodes is known as lymphoid hyperplasia. Traumatic injury to

the abdomen may lead to appendicitis in a

small number of people. Genetics may be a

factor in others. For example, appendicitis

that runs in families may result from a

genetic variant that predisposes a person

to obstruction of the appendiceal lumen.

Symptoms

Symptoms of appendicitis may include 

• pain in the abdomen, first around

the belly button, then moving to the

lower right area

• loss of appetite

• nausea

• vomiting

• constipation or diarrhea

• inability to pass gas

• low fever that begins after other

symptoms

• abdominal swelling

Not everyone with appendicitis has all

the symptoms. The pain intensifies and

worsens when moving, taking deep breaths,

coughing, or sneezing. The area becomes

very tender. People may have a sensation

called “downward urge,” also known as

“tenesmus,” which is the feeling that a

bowel movement will relieve their discomfort. Laxatives and pain medications

should not be taken in this situation.

Anyone with these symptoms needs to 

see a qualified physician immediately.

People With Special Concerns

Patients with special conditions may not

have the set of symptoms above and may

simply experience a general feeling of being

unwell. Patients with these conditions

include

• people who use immunosuppressive

therapy such as steroids

• people who have received a transplanted organ

• people infected with the HIV virus

• people with diabetes

• people who have cancer or who are

receiving chemotherapy

• obese people

Pregnant women, infants and young children, and the elderly have particular issues. 

Abdominal pain, nausea, and vomiting are

more common during pregnancy and may

or may not be the signs of appendicitis.

Many women who develop appendicitis

during pregnancy do not experience the

classic symptoms. Pregnant women who

experience pain on the right side of the

abdomen need to contact a doctor. Women

in their third trimester are most at risk.

Infants and young children cannot communicate their pain history to parents or doctors. Without a clear history, doctors must

rely on a physical exam and less specific

symptoms, such as vomiting and fatigue.

Toddlers with appendicitis sometimes have

trouble eating and may seem unusually

sleepy. Children may have constipation,

but may also have small stools that contain

mucus. Symptoms vary widely among children. If you think your child has appendicitis, contact a doctor immediately. 

2 Appendicitis
Older patients tend to have more medical

problems than young patients. The elderly

often experience less fever and less severe

abdominal pain than other patients do.

Many older adults do not know that they

have a serious problem until the appendix

is close to rupturing. A slight fever and

abdominal pain on one’s right side are

reasons to call a doctor right away.

All patients with special concerns and their

families need to be particularly alert to a

change in normal functioning and patients

should see their doctors sooner, rather than

later, when a change occurs.

Diagnosis

Medical History and Physical

Examination

Asking questions to learn the history of

symptoms and a careful physical examination are key in the diagnosis of appendicitis.

The doctor will ask many questions—much

like a reporter—trying to understand the

nature, timing, location, pattern, and severity of pain and symptoms. Any previous

medical conditions and surgeries, family

history, medications, and allergies are

important information to the doctor. Use

of alcohol, tobacco, and any other drugs

should also be mentioned. This information is considered confidential and cannot

be shared without the permission of the

patient.

Before beginning a physical examination,

a nurse or doctor will usually measure vital

signs: temperature, pulse rate, breathing

rate, and blood pressure. Usually the physical examination proceeds from head to

toe. Many conditions such as pneumonia

or heart disease can cause abdominal pain.

Generalized symptoms such as fever, rash,

or swelling of the lymph nodes may point to

diseases that wouldn’t require surgery.

Examination of the abdomen helps narrow

the diagnosis. Location of the pain and

tenderness is important. Pain is a symptom

described by a patient; tenderness is the

response to being touched. Two signs,

called peritoneal signs, suggest that the

lining of the abdomen is inflamed and surgery may be needed: rebound tenderness

and guarding. Rebound tenderness is

when the doctor presses on a part of the

abdomen and the patient feels more tenderness when the pressure is released than

when it is applied. Guarding refers to the

tensing of muscles in response to touch.

The doctor may also move the patient’s legs

to test for pain on flexion of the hip (psoas

sign), pain on internal rotation of the hip

(obturator sign), or pain on the right side

when pressing on the left (Rovsing’s sign).

These are valuable indicators of inflammation but not all patients have them.

Laboratory Tests

Blood tests are used to check for signs of

infection, such as a high white blood cell

count. Blood chemistries may also show

dehydration or fluid and electrolyte disorders. Urinalysis is used to rule out a urinary

tract infection. Doctors may also order a

pregnancy test for women of childbearing

age (those who have regular periods).

Imaging Tests

X rays, ultrasound, and computed tomography (CT) scans can produce images of the

abdomen. Plain x rays can show signs of

obstruction, perforation (a hole), foreign

bodies, and in rare cases, an appendicolith,

which is hardened stool in the appendix.

Ultrasound may show appendiceal inflammation and can diagnose gall bladder

disease and pregnancy. By far the most

common test used, however, is the CT scan.

This test provides a series of cross-sectional

images of the body and can identify many

3 Appendicitis
abdominal conditions and facilitate diagnosis when the clinical impression is in doubt.

All women of childbearing age should have

a pregnancy test before undergoing any

testing with x rays.

In selected cases, particularly in women

when the cause of the symptoms may be

either the appendix or an inflamed ovary or

fallopian tube, laparoscopy may be necessary. This procedure avoids radiation, but

requires general anesthesia. A laparoscope

is a thin tube with a camera attached that is

inserted into the body through a small cut,

allowing doctors to see the internal organs.

Surgery can then be performed laparoscopically if the condition present requires it. 

Treatment

Surgery

Acute appendicitis is treated by surgery to

remove the appendix. The operation may

be performed through a standard small

incision in the right lower part of the

abdomen, or it may be performed using a

laparoscope, which requires three to four

smaller incisions. If other conditions are

suspected in addition to appendicitis, they

may be identified using laparoscopy. In

some patients, laparoscopy is preferable to

open surgery because the incision is smaller, recovery time is quicker, and less pain

medication is required. The appendix is

almost always removed, even if it is found

to be normal. With complete removal, any

later episodes of pain will not be attributed

to appendicitis.

Recovery from appendectomy takes a few

weeks. Doctors usually prescribe pain

medication and ask patients to limit physical activity. Recovery from laparoscopic

appendectomy is generally faster, but limiting strenuous activity may still be necessary

for 4 to 6 weeks after surgery. Most people

treated for appendicitis recover excellently

and rarely need to make any changes in

their diet, exercise, or lifestyle.

Antibiotics and Other

Treatments

If the diagnosis is uncertain, people may

be watched and sometimes treated with

antibiotics. This approach is taken when

the doctor suspects that the patient’s symptoms may have a nonsurgical or medically

treatable cause. If the cause of the pain is

infectious, symptoms resolve with intravenous antibiotics and intravenous fluids.

In general, however, appendicitis cannot

be treated with antibiotics alone and will

require surgery.

Occasionally the body is able to control

an appendiceal perforation by forming an

abscess. An abscess occurs when an infection is walled off in one part of the body.

The doctor may choose to drain the abscess

and leave the drain in the abscess cavity for

several weeks. An appendectomy may be

scheduled after the abscess is drained.

Complications

The most serious complication of appendicitis is rupture. The appendix bursts

or tears if appendicitis is not diagnosed

quickly and goes untreated. Infants, young

children, and older adults are at highest

risk. A ruptured appendix can lead to

peritonitis and abscess. Peritonitis is a

dangerous infection that happens when

bacteria and other contents of the torn

appendix leak into the abdomen. In people

with appendicitis, an abscess usually takes

the form of a swollen mass filled with fluid

and bacteria. In a few patients, complications of appendicitis can lead to organ

failure and death.

4 Appendicitis
5 Appendicitis

Hope Through Research

The National Institute of Diabetes and

Digestive and Kidney Diseases (NIDDK)

conducts and supports research into many

kinds of digestive disorders, including some

related to appendicitis.

For More Information

American Academy of Family Physicians 

P.O. Box 11210 

Shawnee Mission, KS 66207–1210

Phone: 1–800–274–2237

Email: fp@aafp.org

Internet: www.aafp.org

American College of Surgeons

633 North Saint Clair Street

Chicago, IL 60611–3211

Phone: (312) 202–5000

Fax: (312) 202–5001

Email: postmaster@facs.org

Internet: www.facs.org 

American Society of Colon and Rectal

Surgeons (ASCRS) 

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

National Library of Medicine—

MEDLINEplus

Internet: www.nlm.nih.gov/medlineplus

Points to Remember

• The appendix is a small, tube-like

structure attached to the first part of

the colon. Appendicitis is an inflammation of the appendix.

• Appendicitis is considered a medical

emergency.

• Symptoms of appendicitis include

pain in the abdomen, loss of

appetite, nausea, vomiting, constipation or diarrhea, inability to pass

gas, low-grade fever, and abdominal

swelling. Not everyone with appendicitis has all the symptoms.

• Physical examination, laboratory

tests, and imaging tests are used

to diagnose appendicitis.

• Acute appendicitis is treated by

surgery to remove the appendix.

• The most serious complication of

appendicitis is rupture, which can

lead to peritonitis and abscess.
U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES

National Institutes of Health

NIH Publication No. 04–4547

June 2004

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Phone: 1–800–891–5389 or (301) 654–3810

Fax: (301) 907–8906

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Internet: www.digestive.niddk.nih.gov

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Clearinghouse (NDDIC) is a service of the

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and Kidney Diseases (NIDDK). The NIDDK

is part of the National Institutes of Health

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clearinghouse provides information about

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disorders and to their families, health care

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Publications produced by the clearinghouse are

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Washington University Medical Center.

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This fact sheet is also available at www.

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