Gallstones
 National Digestive Diseases Information Clearinghouse 

National 

Institute of 

Diabetes and 

Digestive 

and Kidney 

Diseases 

NATIONAL 

INSTITUTES 

OF HEALTH 

U.S. Department 

of Health and 

Human Services 

What are gallstones? 

Gallstones are small, pebble-like substances 

that develop in the gallbladder. The gallbladder is a small, pear-shaped sac located 

below your liver in the right upper abdomen. Gallstones form when liquid stored 

in the gallbladder hardens into pieces of 

stone-like material. The liquid—called 

bile—helps the body digest fats. Bile is 

made in the liver, then stored in the gallbladder until the body needs it. The gallbladder contracts and pushes the bile into 

a tube—called the common bile duct—that 

carries it to the small intestine, where it 

helps with digestion. 

Bile contains water, cholesterol, fats, bile 

salts, proteins, and bilirubin—a waste product. Bile salts break up fat, and bilirubin 

gives bile and stool a yellowish-brown color. 

If the liquid bile contains too much cholesterol, bile salts, or bilirubin, it can harden 

into gallstones. 

The two types of gallstones are cholesterol 

stones and pigment stones. Cholesterol 

stones are usually yellow-green and are 

made primarily of hardened cholesterol. 

They account for about 80 percent of 

gallstones. Pigment stones are small, dark 

stones made of bilirubin. Gallstones can be 

as small as a grain of sand or as large as a 

golf ball. The gallbladder can develop just 

one large stone, hundreds of tiny stones, or 

a combination of the two. 

Gallstones can block the normal flow of bile 

if they move from the gallbladder and lodge 

in any of the ducts that carry bile from 

the liver to the small intestine. The ducts 

include the 

•	 hepatic	ducts,	which	carry	bile	out	of	

the liver 

•	 cystic	duct,	which	takes	bile	to	and	

from the gallbladder 

•	 common	bile	duct,	which	takes	bile	

from the cystic and hepatic ducts to the 

small intestine 

Gallbladder 

Duodenum 

Hepatic ducts 

Cystic duct 

Pancreas 

Common bile duct 

Pancreatic duct 

Liver 

The gallbladder and the ducts that carry bile and 

other digestive enzymes from the liver, gallbladder, and 

pancreas to the small intestine are called the biliary 

system. 

Bile trapped in these ducts can cause 

inflammation in the gallbladder, the ducts, 

or in rare cases, the liver. Other ducts open 

into the common bile duct, including the 

pancreatic duct, which carries digestive 
enzymes out of the pancreas. Sometimes 

gallstones passing through the common 

bile duct provoke inflammation in the 

pancreas—called gallstone pancreatitis— 

an extremely painful and potentially 

dangerous condition. 

If any of the bile ducts remain blocked for 

a significant period of time, severe damage or infection can occur in the gallbladder, liver, or pancreas. Left untreated, the 

condition can be fatal. Warning signs of a 

serious problem are fever, jaundice, and 

persistent pain. 

What causes gallstones? 

Scientists believe cholesterol stones form 

when bile contains too much cholesterol, 

too much bilirubin, or not enough bile salts, 

or when the gallbladder does not empty 

completely or often enough. The reason 

these imbalances occur is not known. 

The cause of pigment stones is not fully 

understood. The stones tend to develop in 

people who have liver cirrhosis, biliary tract 

infections, or hereditary blood disorders— 

such as sickle cell anemia—in which the 

liver makes too much bilirubin. 

The mere presence of gallstones may 

cause more gallstones to develop. Other 

factors that contribute to the formation of 

gallstones, particularly cholesterol stones, 

include 

•	 Sex. Women are twice as likely as men 

to develop gallstones. Excess estrogen 

from pregnancy, hormone replacement therapy, and birth control pills 

appears to increase cholesterol levels 

in bile and decrease gallbladder movement, which can lead to gallstones. 

•	 Family history. Gallstones often run 

in families, pointing to a possible 

genetic link. 

•	 Weight. A large clinical study showed 

that being even moderately overweight increases the risk for developing gallstones. The most likely reason 

is that the amount of bile salts in bile 

is reduced, resulting in more cholesterol. Increased cholesterol reduces 

gallbladder emptying. Obesity is a 

major risk factor for gallstones, especially in women. 

•	 Diet. Diets high in fat and cholesterol 

and low in fiber increase the risk of 

gallstones due to increased cholesterol 

in the bile and reduced gallbladder 

emptying. 

•	 Rapid weight loss. As the body 

metabolizes fat during prolonged 

fasting and rapid weight loss—such as 

“crash diets”—the liver secretes extra 

cholesterol into bile, which can cause 

gallstones. In addition, the gallbladder does not empty properly. 

•	 Age. People older than age 60 are 

more likely to develop gallstones than 

younger people. As people age, the 

body tends to secrete more cholesterol 

into bile. 

•	 Ethnicity. American Indians have a 

genetic predisposition to secrete high 

levels of cholesterol in bile. In fact, 

they have the highest rate of gallstones 

in the United States. The majority of 

American Indian men have gallstones 

by age 60. Among the Pima Indians 

of Arizona, 70 percent of women 

have gallstones by age 30. Mexican 

American men and women of all ages 

also have high rates of gallstones. 

2 Gallstones 
•	 Cholesterol-lowering drugs. Drugs 

that lower cholesterol levels in the 

blood actually increase the amount of 

cholesterol secreted into bile. In turn, 

the risk of gallstones increases. 

•	 Diabetes. People with diabetes generally have high levels of fatty acids 

called triglycerides. These fatty acids 

may increase the risk of gallstones. 

Who is at risk for 

gallstones? 

People at risk for gallstones include 

•	 women—especially	women	

who are pregnant, use hormone 

replacement therapy, or take birth 

control pills 

•	 people	over	age	60	

•	 American	Indians	

•	 Mexican	Americans	

•	 overweight	or	obese	men	and	

women 

•	 people	who	fast	or	lose	a	lot	of	

weight quickly 

•	 people	with	a	family	history	of	

gallstones 

•	 people	with	diabetes

•	 people	who	take	cholesterollowering drugs 

What are the symptoms of 

gallstones? 

As gallstones move into the bile ducts 

and create blockage, pressure increases 

in the gallbladder and one or more symptoms may occur. Symptoms of blocked 

bile ducts are often called a gallbladder 

“attack” because they occur suddenly. 

Gallbladder attacks often follow fatty 

meals, and they may occur during the 

night. A typical attack can cause 

•	 steady	pain	in	the	right	upper	abdomen that increases rapidly and lasts 

from 30 minutes to several hours 

•	 pain	in	the	back	between	the	shoulder	

blades 

•	 pain	under	the	right	shoulder	

Notify your doctor if you think you 

have experienced a gallbladder attack. 

Although these attacks often pass as 

gallstones move, your gallbladder can 

become infected and rupture if a blockage 

remains. 

People with any of the following symptoms 

should see a doctor immediately: 

•	 prolonged	pain—more	than	5	hours

•	 nausea	and	vomiting		

•	 fever—even	low-grade—or	chills	

•	 yellowish	color	of	the	skin	or	whites	

of the eyes 

•	 clay-colored	stools	

3 Gallstones 
Many people with gallstones have no symptoms; these gallstones are called “silent 

stones.” They do not interfere with gallbladder, liver, or pancreas function and do 

not need treatment. 

How are gallstones 

diagnosed? 

Frequently, gallstones are discovered during tests for other health conditions. When 

gallstones are suspected to be the cause 

of symptoms, the doctor is likely to do an 

ultrasound exam—the most sensitive and 

specific test for gallstones. A handheld 

device, which a technician glides over the 

abdomen, sends sound waves toward the 

gallbladder. The sound waves bounce off 

the gallbladder, liver, and other organs, 

and their echoes make electrical impulses 

that create a picture of the gallbladder on 

a video monitor. If gallstones are present, 

the sound waves will bounce off them, too, 

showing their location. Other tests may 

also be performed. 

•	 Computerized tomography (CT) 

scan. The CT scan is a noninvasive 

x ray that produces cross-section 

images of the body. The test may 

show the gallstones or complications, 

such as infection and rupture of the 

gallbladder or bile ducts. 

•	 Cholescintigraphy (HIDA scan). The 

patient is injected with a small amount 

of nonharmful radioactive material 

that is absorbed by the gallbladder, 

which is then stimulated to contract. 

The test is used to diagnose abnormal contraction of the gallbladder or 

obstruction of the bile ducts. 

•	 Endoscopic retrograde cholangiopancreatography (ERCP). ERCP is used 

to locate and remove stones in the bile 

ducts. After lightly sedating you, the 

doctor inserts an endoscope—a long, 

flexible, lighted tube with a camera— 

down the throat and through the stomach and into the small intestine. The 

endoscope is connected to a computer 

and video monitor. The doctor guides 

the endoscope and injects a special dye 

that helps the bile ducts appear better 

on the monitor. The endoscope helps 

the doctor locate the affected bile 

duct and the gallstone. The stone is 

captured in a tiny basket and removed 

with the endoscope. 

•	 Blood tests. Blood tests may be performed to look for signs of infection, 

obstruction, pancreatitis, or jaundice. 

Because gallstone symptoms may be similar to those of a heart attack, appendicitis, 

ulcers, irritable bowel syndrome, hiatal hernia, pancreatitis, and hepatitis, an accurate 

diagnosis is important. 

4 Gallstones 
How are gallstones treated? 

Surgery 

If you have gallstones without symptoms, 

you do not require treatment. If you are 

having frequent gallbladder attacks, your 

doctor will likely recommend you have your 

gallbladder removed—an operation called 

a cholecystectomy. Surgery to remove the 

gallbladder—a nonessential organ—is one 

of the most common surgeries performed 

on adults in the United States. 

Nearly all cholecystectomies are performed 

with laparoscopy. After giving you medication to sedate you, the surgeon makes 

several tiny incisions in the abdomen and 

inserts a laparoscope and a miniature 

video camera. The camera sends a magnified image from inside the body to a video 

monitor, giving the surgeon a close-up view 

of the organs and tissues. While watching 

the monitor, the surgeon uses the instruments to carefully separate the gallbladder 

from the liver, bile ducts, and other structures. Then the surgeon cuts the cystic duct 

and removes the gallbladder through one of 

the small incisions. 

Recovery after laparoscopic surgery usually involves only one night in the hospital, 

and normal activity can be resumed after a 

few days at home. Because the abdominal 

muscles are not cut during laparoscopic 

surgery, patients have less pain and fewer 

complications than after “open” surgery, 

which	requires	a	5-	to	8-inch	incision	across	

the abdomen. 

If tests show the gallbladder has severe 

inflammation, infection, or scarring from 

other operations, the surgeon may perform open surgery to remove the gallbladder. In some cases, open surgery is 

planned; however, sometimes these problems are discovered during the laparoscopy and the surgeon must make a larger 

incision. Recovery from open surgery 

usually	requires	3	to	5	days	in	the	hospital	

and several weeks at home. Open surgery 

is	necessary	in	about	5	percent	of	gallbladder operations. 

The most common complication in gallbladder surgery is injury to the bile ducts. 

An injured common bile duct can leak 

bile and cause a painful and potentially 

dangerous infection. Mild injuries can 

sometimes be treated nonsurgically. 

Major injury, however, is more serious and 

requires additional surgery. 

If gallstones are present in the bile ducts, 

the physician—usually a gastroenterologist—may use ERCP to locate and remove 

them before or during gallbladder surgery. 

Occasionally, a person who has had a cholecystectomy is diagnosed with a gallstone 

in the bile ducts weeks, months, or even 

years after the surgery. The ERCP procedure is usually successful in removing the 

stone in these cases. 

5		Gallstones
 
Do people need their 

gallbladder? 

Fortunately, the gallbladder is an 

organ people can live without. Your 

liver produces enough bile to digest 

a normal diet. Once the gallbladder 

is removed, bile flows out of the liver 

through the hepatic ducts into the 

common bile duct and directly into the 

small intestine, instead of being stored 

in the gallbladder. Because now the 

bile flows into the small intestine more 

often, softer and more frequent stools 

can occur in about 1 percent of people. 

These changes are usually temporary, 

but talk with your health care provider 

if they persist. 

Nonsurgical Treatment 

Nonsurgical approaches are used only in 

special situations—such as when a patient 

has a serious medical condition preventing 

surgery—and only for cholesterol stones. 

Stones	commonly	recur	within	5	years	in	

patients treated nonsurgically. 

•	 Oral dissolution therapy. Drugs made 

from bile acid are used to dissolve 

gallstones. The drugs ursodiol (Actigall) and chenodiol (Chenix) work best 

for small cholesterol stones. Months 

or years of treatment may be necessary before all the stones dissolve. 

Both drugs may cause mild diarrhea, 

and chenodiol may temporarily raise 

levels of blood cholesterol and the liver 

enzyme transaminase. 

•	 Contact dissolution therapy. This 

experimental procedure involves 

injecting a drug directly into the gallbladder to dissolve cholesterol stones. 

The drug—methyl tert-butyl ether— 

can dissolve some stones in 1 to 3 days, 

but it causes irritation and some complications have been reported. The 

procedure is being tested in symptomatic patients with small stones. 

6 Gallstones 
7 Gallstones

Points to Remember

•	 Gallstones form when bile hardens in the gallbladder.

•	 Gallstones are more common

among older adults; women; 

American Indians; Mexican 

Americans; people with diabetes; 

those with a family history of 

gallstones; people who are 

overweight, obese, or undergo 

rapid weight loss; and those 

taking cholesterol-lowering drugs. 

•	 Gallbladder attacks often occur

after eating a meal, especially one 

high in fat.

•	 Symptoms can mimic those of

other problems, including a heart 

attack, so an accurate diagnosis is 

important.

•	 Gallstones can cause serious

problems if they become trapped 

in the bile ducts.

•	 Laparoscopic surgery to remove

the gallbladder is the most common treatment.

Hope Through Research

Animal research has helped identify several 

genes that may determine which people are 

more prone to gallstones. In spite of many 

well-defined risk factors for gallstones, 

researchers continue to look for genes 

that may identify susceptibility in humans. 

Researchers also believe that the growing 

global epidemic of obesity may increase 

rates of gallbladder disease worldwide.

You may also find additional information about this 

topic by visiting MedlinePlus at www.medlineplus.gov.

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medications used to treat a health condition. When 

this publication was prepared, the NIDDK included 

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For updates or for questions about any medications, 

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document are used only because they are considered 

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If a product is not mentioned, the omission does not 

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U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES 

National Institutes of Health 

NIH Publication No. 07–2897 

July 2007