What Are Gallstones?
Gallstones form when liquid stored in the gallbladder hardens into
pieces of stone-like material. The liquid, called bile, is used to help
the body digest fats. Bile is made in the liver, then stored in the
gallbladder until the body needs to digest fat. At that time, 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
Bile contains water, cholesterol, fats, bile salts, proteins, and
bilirubin. Bile salts break up fat, and bilirubin gives bile and stool a
yellowish color. If the liquid bile contains too much cholesterol, bile
salts, or bilirubin, under certain conditions it can harden into
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 almost any
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
Gallstones can block the normal flow of bile if they lodge in any of
the ducts that carry bile from the liver to the small intestine. That
includes the hepatic ducts, which carry bile out of the liver; the cystic
duct, which takes bile to and from the gallbladder; and the common bile
duct, which takes bile from the cystic and hepatic ducts to the small
intestine. Bile trapped in these ducts can cause inflammation in the
gallbladder, the ducts, or, rarely, the liver. Other ducts open into the
common bile duct, including the pancreatic duct, which carries digestive
enzymes out of the pancreas. If a gallstone blocks the opening to that
duct, digestive enzymes can become trapped in the pancreas and cause an
extremely painful inflammation called gallstone pancreatitis.
If any of these ducts remain blocked for a significant period of time,
severe--possibly fatal--damage or infections can occur, affecting the
gallbladder, liver, or pancreas. 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 as it should for some
The cause of pigment stones is uncertain. They
tend to develop in people who have cirrhosis, biliary tract infections,
and hereditary blood disorders such as sickle cell anemia in which too
much bilirubin is formed.
It is believed that the mere presence of
gallstones may cause more gallstones to develop. However, other factors
that contribute to gallstones have been identified, especially for
- Obesity. Obesity is a major risk factor for gallstones,
especially in women. A large clinical study showed that being even
moderately overweight increases one's risk for developing gallstones.
The most likely reason is that obesity tends to reduce the amount of
bile salts in bile, resulting in more cholesterol. Obesity also
decreases gallbladder emptying.
- Estrogen. Excess estrogen from pregnancy, hormone replacement
therapy, or birth control pills appears to increase cholesterol levels
in bile and decrease gallbladder movement, both of which can lead to
- Ethnicity. Native Americans 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. A majority of Native
American 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.
- Gender. Women between 20 and 60 years of age are twice as
likely to develop gallstones as men.
- Age. People over age 60 are more likely to develop gallstones
than younger people.
- Cholesterol-lowering drugs. Drugs that lower cholesterol
levels in blood actually increase the amount of cholesterol secreted in
bile. This in turn can increase the risk of gallstones.
- Diabetes. People with diabetes generally have high levels of
fatty acids called triglycerides. These fatty acids increase the risk of
- Rapid weight loss. As the body metabolizes fat during rapid
weight loss, it causes the liver to secrete extra cholesterol into bile,
which can cause gallstones.
- Fasting. Fasting decreases gallbladder movement, causing the
bile to become overconcentrated with cholesterol, which can lead to
Who Is at Risk for Gallstones?
- people over age 60
- Native Americans
- Mexican Americans
- overweight men and women
- people who fast or lose a lot of weight quickly
- pregnant women, women on hormone therapy, and women who use
birth control pills
What Are the Symptoms?
Symptoms of gallstones are often called a gallstone "attack" because
they occur suddenly. A typical attack can cause
- steady pain in the 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
- nausea or vomiting
Gallstone attacks often follow fatty meals, and they may occur during
the night. Other gallstone symptoms include
- abdominal bloating
- recurring intolerance of fatty foods
People who also have the above and any of following symptoms should see
a doctor right away:
- low-grade fever
- yellowish color of the skin or whites of the eyes
- clay-colored stools
Many people with gallstones have no symptoms. These patients are said
to be asymptomatic, and these stones are called "silent stones." They do
not interfere in gallbladder, liver, or pancreas function and do not need
How Are Gallstones Diagnosed?
Many gallstones, especially silent stones, are discovered by accident
during tests for other problems. But when gallstones are suspected to be
the cause of symptoms, the doctor is likely to do an ultrasound exam.
Ultrasound uses sound waves to create images of organs. Sound waves are
sent toward the gallbladder through a handheld device that a technician
glides over the abdomen. The sound waves bounce off the gallbladder,
liver, and other organs such as a pregnant uterus, and their echoes make
electrical impulses that create a picture of the organ on a video monitor.
If stones are present, the sound waves will bounce off them, too, showing
their location. Ultrasound is the most sensitive and specific test for
Other tests used in diagnosis include
- Computed tomography (CT) scan may show the gallstones or
- MR cholangiogram may diagnose blocked bile ducts.
- Cholescintigraphy (HIDA scan) is used to diagnose abnormal
contraction of the gallbladder or obstruction. The patient is injected
with a radioactive material that is taken up in the gallbladder, which
is then stimulated to contract.
- Endoscopic retrograde cholangiopancreatography (ERCP). The
patient swallows an endoscope--a long, flexible, lighted tube connected
to a computer and TV monitor. The doctor guides the endoscope through
the stomach and into the small intestine. The doctor then injects a
special dye that temporarily stains the ducts in the biliary system.
ERCP is used to locate and remove stones in the ducts.
- Blood tests. Blood tests may be used to look for signs of
infection, obstruction, pancreatitis, or jaundice.
Gallstone symptoms are similar to those of heart attack, appendicitis,
ulcers, irritable bowel syndrome, hiatal hernia, pancreatitis, and
hepatitis. So accurate diagnosis is important.
What Is the Treatment?
Surgery to remove the gallbladder is the most common way to treat
symptomatic gallstones. (Asymptomatic gallstones usually do not need
treatment.) Each year more than 500,000 Americans have gallbladder
surgery. The surgery is called cholecystectomy.
The most common operation is called laparoscopic cholecystectomy. For
this operation, the surgeon makes several tiny incisions in the abdomen
and inserts surgical instruments and a miniature video camera into the
abdomen. The camera sends a magnified image from inside the body to a
video monitor, giving the surgeon a closeup view of the organs and
tissues. While watching the monitor, the surgeon uses the instruments to
carefully separate the gallbladder from the liver, ducts, and other
structures. Then the cystic duct is cut and the gallbladder removed
through one of the small incisions.
Because the abdominal muscles are not cut during laparoscopic surgery,
patients have less pain and fewer complications than they would have had
after surgery using a large incision across the abdomen. Recovery usually
involves only one night in the hospital, followed by several days of
restricted activity at home.
If the surgeon discovers any obstacles to the laparoscopic procedure,
such as infection or scarring from other operations, the operating team
may have to switch to open surgery. In some cases the obstacles are known
before surgery, and an open surgery is planned. It is called "open"
surgery because the surgeon has to make a 5- to 8-inch incision in the
abdomen to remove the gallbladder. This is a major surgery and may require
about a 2- to 7-day stay in the hospital and several more weeks at home to
recover. Open surgery is required in about 5 percent of gallbladder
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
If gallstones are in the bile ducts, the physician (usually a
gastroenterologist) may use endoscopic retrograde cholangiopancreatography
(ERCP) to locate and remove them before or during the gallbladder surgery.
In ERCP, the patient swallows an endoscope--a long, flexible, lighted tube
connected to a computer and TV monitor. The doctor guides the endoscope
through the stomach and into the small intestine. The doctor then injects
a special dye that temporarily stains the ducts in the biliary system.
Then the affected bile duct is located and an instrument on the endoscope
is used to cut the duct. The stone is captured in a tiny basket and
removed with the endoscope.
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 two-step ERCP procedure is usually successful in removing the
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 usually recur after nonsurgical
- Oral dissolution therapy. Drugs made from bile acid are used
to dissolve the stones. 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
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
stones. The drug--methyl tertbutyl ether--can dissolve some stones in 1
to 3 days, but it must be used very carefully because it is a flammable
anesthetic that can be toxic. The procedure is being tested in patients
with symptomatic, noncalcified cholesterol stones.
- Extracorporeal shockwave lithotripsy (ESWL). This treatment
uses shock waves to break up stones into tiny pieces that can pass
through the bile ducts without causing blockages. Attacks of biliary
colic (intense pain) are common after treatment, and ESWL's success rate
is not known. This approach is usually combined with therapeutic
Don't People Need Their Gallbladders?
Fortunately, the gallbladder is an organ that people can live
without. Losing it won't even require a change in diet. Once the
gallbladder is removed, bile flows out of the liver through the
hepatic ducts into the common bile duct and goes directly into the
small intestine, instead of being stored in the gallbladder.
However, because the bile isn't stored in the gallbladder, it flows
into the small intestine more frequently, causing diarrhea in about
1 percent of people.
Points to Remember
- Gallstones form when substances in the bile harden.
- Gallstones are more common among women, Native Americans, Mexican
Americans, and people who are overweight.
- Gallstone attacks often occur after eating a meal.
- Symptoms can mimic those of other problems, including heart attack,
so accurate diagnosis is important.
- Gallstones can cause serious problems if they become trapped in the
- Laparoscopic surgery to remove the gallbladder is the most common
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
A new service available to patients provides a convenient means of staying informed, and ensures that the information is both reliable and accurate. If you wish to find out more about HealthNewsflash's innovative service, take the tour.