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
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 digestion.
Bile contains water, cholesterol, fats, bile salts, proteins, and bilirubin. Bile salts break upfat, 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 stones.
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 combination.
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.
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
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.
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.
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 other reason.
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
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 cholesterol stones.
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.
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
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.
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.
Women between 20 and 60 years of age are twice as likely to
develop gallstones as men.
People over age 60 are more likely to develop gallstones than
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.
People with diabetes generally have high levels of fatty acids
called triglycerides. These fatty acids increase the risk of
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 decreases gallbladder movement, causing the bile to
become over concentrated with cholesterol, which can lead to
Who is at
risk for gallstones?
over age 60
men and women
who fast or lose a lot of weight quickly
women, women on hormone therapy, and women who use birth control
of gallstones are often called a gallstone "attack"
because they occur suddenly. A typical attack can cause:
pain in the upper abdomen that increases rapidly and lasts from
30 minutes to several hours
the back between the shoulder blades
under the right shoulder
or vomiting Gallstone attacks often follow fatty meals, and they
may occur during the night. Other gallstone symptoms include:
intolerance of fatty foods
People who also have the above and any of following symptoms
should see a doctor right away:
color of the skin or whites of the eyes
stools Many people with gallstones have no symptoms. These
patients are said to be a symptomatic, and these stones are
called "silent stones." They do not interfere in
gallbladder, liver, or pancreas function and do not need
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.
waves are sent toward the gallbladder through a handheld device
that a technician glides over the abdomen.
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.
is the most sensitive and specific test for gallstones. Other
tests used in diagnosis include:
tomography (CT) scan may show the gallstones or complications.
cholangiogram may diagnose blocked bile ducts.
(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.
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
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
remove the gallbladder is the most common way to treat symptomatic
gallstones. (A symptomatic gallstones usually do not need
treatment.) Each year more than 500,000 Americans have gallbladder
surgery. The surgery is called cholecystectomy.
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 close up view of the organs
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.
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.
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.
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
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 operations. The most
common complication in gallbladder surgery is injury to the bile
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
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.
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
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 stone.
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
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
drugs cause mild diarrhea, and chenodiol may temporarily raise
levels of blood cholesterol and the liver enzyme transaminase.
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.
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 ERCP.
people need their gallbladders?
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.
because the bile isn't stored in the gallbladder, it flows into the
small intestine more frequently, causing diarrhea in about 1 percent
form when substances in the bile harden.
are more common among women, Native Americans, Mexican
Americans, and people who are overweight.
attacks often occur after eating a meal.
can mimic those of other problems, including heart attack, so
accurate diagnosis is important.
can cause serious problems if they become trapped in the bile
surgery to remove the gallbladder is the most common treatment. The
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