What are gallstones?
A gallstone is a stone formed within the gallbladder out of bile components. The term cholelithiasis may refer to the presence of gallstones or to the diseases caused by gallstones. Most people with gallstones (about 80%) never have symptoms. When a gallstone blocks the bile duct, a cramp-like pain in the right upper part of the abdomen, known as biliary colic (gallbladder attack) can result. This happens in 1–4% of those with gallstones each year. Complications of gallstones may include inflammation of the gallbladder (cholecystitis), inflammation of the pancreas (pancreatitis), jaundice, and infection of a bile duct (cholangitis). Symptoms of these complications may include pain of more than five hours duration, fever, yellowish skin, vomiting, dark urine, and pale stools.
Risk factors for gallstones include birth control pills, pregnancy, a family history of gallstones, obesity, diabetes, liver disease, or rapid weight loss. The bile components that form gallstones include cholesterol, bile salts, and bilirubin. Gallstones formed mainly from cholesterol are termed cholesterol stones, and those mainly from bilirubin are termed pigment stones. Gallstones may be suspected based on symptoms. Diagnosis is then typically confirmed by ultrasound. Complications may be detected on blood tests.
The risk of gallstones may be decreased by maintaining a healthy weight with exercise and a healthy diet. If there are no symptoms, treatment is usually not needed. In those who are having gallbladder attacks, surgery to remove the gallbladder is typically recommended. This can be carried out either through several small incisions or through a single larger incision, usually under general anesthesia. In rare cases when surgery is not possible, medication can be used to dissolve the stones or lithotripsy to break them down.
There are two types of gallstones: 1) cholesterol stones and 2) pigment stones.
- Patients with cholesterol stones are more common in the United States; cholesterol stones make up a majority of all gallstones (in the U.S., about 80%). They form when there is too much cholesterol in the bile.
- Pigment stones form when there is excess bilirubin in the bile.
Gallstones can be any size, from tiny as a grain of sand to large as a golf ball.
- Although it is common to have many smaller stones, a single larger stone or any combination of sizes is possible.
- If stones are very small, they may form a sludge or slurry.
- Whether gallstones cause symptoms depends partly on their size and their number, although no combination of number and size can predict whether symptoms will occur or the severity of the symptoms.
What Are Signs and Symptoms of Gallstones?
Most people with gallstones have no symptoms. In fact, they are usually unaware that they have gallstones unless symptoms occur. These “silent gallstones” usually require no treatment.
Symptoms usually occur as complications develop. The most common symptom is pain in the right upper part of the abdomen. Because the pain comes in episodes, it is often referred to as an “attack.”
- Attacks may occur every few days, weeks, or months; they may even be separated by years.
- The pain usually starts within 30 minutes after a fatty or greasy meal.
- The pain is usually severe, dull, and constant, and can last from one to five hours.
- It may radiate to the right shoulder or back.
- It occurs frequently at night and may awaken the person from sleep.
- The pain may make the person want to move around to seek relief, but many patients prefer to lay still and wait for the attack to subside.
Other common symptoms of gallstones include the following:
- nausea and vomiting,
- fever,
- indigestion, belching, bloating,
- intolerance for fatty or greasy foods, and
- jaundice (yellowing of the skin or the whites of the eyes).
Asymptomatic gallstones
Gallstones themselves don’t cause pain. Rather, pain occurs when the gallstones block the movement of bile from the gallbladder.
According to the American College of Gastroenterology, 80 percent of people have “silent gallstones.” This means they don’t experience pain or have symptoms. In these cases, your doctor may discover the gallstones from X-rays or during abdomen surgery.
What Causes Gallstones?
Gallstones occur when bile forms solid particles (stones) in the gallbladder.
- The stones form when the amount of cholesterol or bilirubin in the bile is high.
- Other substances in the bile may promote the formation of stones.
- Pigment stones form most often in people with liver disease or blood disease, who have high levels of bilirubin.
- Poor muscle tone may keep the gallbladder from emptying completely. The presence of residual bile may promote the formation of gallstones.
Risk factors for the formation of cholesterol gallstones include the following:
- female gender,
- being overweight,
- rapid weight loss on a “crash” or starvation diet, or
- taking certain medications such as birth control pills or cholesterol lowering drugs.
Gallstones are the most common cause of gallbladder disease.
- As the stones mix with liquid bile, they can block the outflow of bile from the gallbladder. They can also block the outflow of digestive enzymes from the pancreas.
- If the blockage persists, these organs can become inflamed. Inflammation of the gallbladder is called cholecystitis. Inflammation of the pancreas is called pancreatitis.
- Contraction of the blocked gallbladder causes increased pressure, swelling, and, at times, infection of the gallbladder.
When the gallbladder or gallbladder ducts become inflamed or infected as the result of stones, the pancreas frequently becomes inflamed too.
- This inflammation can cause destruction of the pancreas, resulting in pancreatitis and severe abdominal pain.
- Untreated gallstone disease can become life-threatening, particularly if the gallbladder becomes infected or if the pancreas becomes severely inflamed.
Treatment
Gallstones are only treated if they have caused gallbladder inflammation, blockage of the bile ducts, or if they have moved from the bile ducts into the intestines.
Cholecystectomy
Cholecystectomy means the surgical removal of the gallbladder. This is usually performed with keyhole surgery. Keyhole surgery is not possible for about 10 percent of people who need open cholecystectomy. They will have open surgery instead.
With open cholecystectomy, a large cut is made in the abdomen. People who undergo open surgery require a longer hospital stay and recovery time. If a gallbladder is severely inflamed, open surgery will be needed.
For a large proportion of those who undergo a cholecystectomy, gallstones come back within a year. To help prevent this, many people with gallstones are given ursosdeoxycholic acid, which is the acid found in bile.
Ursosdeoxycholic acid lowers the cholesterol content of bile, making it less likely that stones will form.
Ursodeoxycholic acid
If the gallstone is made of cholesterol, it can sometimes be slowly dissolved with ursodeoxycholic acid. This type of treatment, known as dissolution, may take up to 24 months to be effective. It is not as effective as surgery but is sometimes the only choice for people who cannot have a general anesthetic.
Endoscopic retrograde cholangiopancreatolography
When a person with gallstones cannot have surgery or ursodeoxycholic acid, they may undergo endoscopic retrograde cholangiopancreatolography (ERCP), which requires a local anesthetic. A flexible fiber-optic camera, or endoscope, goes into mouth, through the digestive system, and into the gallbladder.
An electrically heated wire widens the opening of the bile duct. The stones are then removed or left to pass into the intestine.
Lithotripsy
Ultrasonic shock waves are aimed at the gallstones, which break them up. If gallstones become small enough, they can then pass safely in the stools. This type of treatment is uncommon and is only used when there are few gallstones present.
Diagnosis
In many cases, gallstones are discovered by accident when an individual is being treated for a different condition. A doctor may suspect gallstones after a cholesterol test, an ultrasound scan, a blood test, or even an X-ray.
Blood tests may be used to look for signs of infection, obstruction, pancreatitis, or jaundice.
Cholangiography
A dye is either injected into the blood stream so that it concentrates into the bile ducts or gallbladder, or it is inserted straight into the bile ducts using an ERCP. The dye shows up on X-rays. ERCP is also used to locate and remove stones in the bile duct.
The doctor will then be able to look at the X-rays and identify possible gallbladder or bile duct disorders, such as pancreatitis, cancer of the pancreas, or gallstones. The X-rays will indicate to the doctor whether the dye is reaching the liver, bile ducts, intestines, and gallbladder.
If the dye does not move into one of these areas, it generally means that the gallstone is causing a blockage. An expert will have a better idea of where the gallstone is located.
CT scan
This is a non-invasive X-ray that produces cross-section pictures of the inside of the human body.
Cholescintigraphy (HIDA scan)
A small amount of harmless radioactive material is injected into the patient. This is absorbed by the gallbladder, which is then stimulated to contract. This test may diagnose abnormal contractions of the gallbladder or an obstruction of the bile duct.
Risk factors
Factors that may increase your risk of gallstones include:
- Being female
- Being age 40 or older
- Being a Native American
- Being a Mexican American
- Being overweight or obese
- Being sedentary
- Being pregnant
- Eating a high-fat diet
- Eating a high-cholesterol diet
- Eating a low-fiber diet
- Having a family history of gallstones
- Having diabetes
- Having certain blood disorders, such as sickle cell anemia or leukemia
- Losing weight very quickly
- Taking medications that contain estrogen, such as oral contraceptives or hormone therapy drugs
- Having liver disease
Complications
Complications of gallstones may include:
- Inflammation of the gallbladder. A gallstone that becomes lodged in the neck of the gallbladder can cause inflammation of the gallbladder (cholecystitis). Cholecystitis can cause severe pain and fever.
- Blockage of the common bile duct. Gallstones can block the tubes (ducts) through which bile flows from your gallbladder or liver to your small intestine. Severe pain, jaundice and bile duct infection can result.
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Blockage of the pancreatic duct. The pancreatic duct is a tube that runs from the pancreas and connects to the common bile duct just before entering the duodenum. Pancreatic juices, which aid in digestion, flow through the pancreatic duct.
A gallstone can cause a blockage in the pancreatic duct, which can lead to inflammation of the pancreas (pancreatitis). Pancreatitis causes intense, constant abdominal pain and usually requires hospitalization.
- Gallbladder cancer. People with a history of gallstones have an increased risk of gallbladder cancer. But gallbladder cancer is very rare, so even though the risk of cancer is elevated, the likelihood of gallbladder cancer is still very small.
Prevention
You can reduce your risk of gallstones if you:
- Don’t skip meals. Try to stick to your usual mealtimes each day. Skipping meals or fasting can increase the risk of gallstones.
- Lose weight slowly. If you need to lose weight, go slow. Rapid weight loss can increase the risk of gallstones. Aim to lose 1 or 2 pounds (about 0.5 to 1 kilogram) a week.
- Eat more high-fiber foods. Include more fiber-rich foods in your diet, such as fruits, vegetables and whole grains.
- Maintain a healthy weight. Obesity and being overweight increase the risk of gallstones. Work to achieve a healthy weight by reducing the number of calories you eat and increasing the amount of physical activity you get. Once you achieve a healthy weight, work to maintain that weight by continuing your healthy diet and continuing to exercise.