Gallstones are stones or lumps that develop in the gallbladder or bile duct when substances in there harden.
Researchers from the Keck School of Medicine of USC describe a gallstone in the bile duct as similar to trying to squeeze a golf ball through a straw.
There are approximately 20 million Americans with gallstones. A study revealed that the prevalence of gallstones in adults in industrialized countries is approximately 10% and is showing a tendency to rise.
In order to better understand what gallstones are, we need to discuss the role of the gallbladder and the bile ducts.
What is the gallbladder?
The gallbladder is a small sac located on the right-hand side of the body, on the underside of the liver. Gall (bile) is a greenish-brown liquid which the liver produces. Gall is stored and concentrated in the gallbladder. Gall goes into the small intestine via the bile ducts to facilitate the digestion, mainly of fats. Every time we eat some gall is released into the intestines. The bile duct is a narrow tube.
What are gallstones?
When the chemicals in the gallbladder, cholesterol, calcium bilirubinate, and calcium carbonate are out of balance gallstones may form.
There are two main types of gallstones:
- Cholesterol gallstones - these may form if there is too much cholesterol in the bile? They are the main type of gallstones in the UK and the USA.
- Pigment gallstones - these form when the bile has too much bilirubin. They are more common among patients who have liver disease, infected bile tubes or blood disorders, such as sickle-cell anemia.
Causes of gallstones
Experts are not completely sure why some people develop a chemical imbalance in their gallbladder which causes gallstones, while others do not. However, we do know that gallstones are more common among:
Overweight/obese people, especially women. A study revealed that a bulging midriff almost doubles a woman's chances of developing gallstones and the need for surgery to remove them.
Obese children have a considerably higher risk of developing gallstones, compared to kids of normal weight, researchers from Kaiser Permanents reported in the Journal of Pediatric Gastroenterology & Nutrition (August 2012 issue).
- Women who have been pregnant
- People who have recently lost lots of weight
- Intentionally losing weight and then regaining it may increase men's risk for gallstones later in life
- Women taking oral contraceptives
- Women undergoing high-dose estrogen therapy
- People with a close relative who has had gallstones
- A study revealed that a gene variant significantly increases the risk of developing gallstones
- People whose intake of dietary fat is high
- Twice as many women get gallstones than men
- People over 60 years of age
- Native American Indians
- People who take statins (cholesterol-lowering drugs)
- People with diabetes
- Hormone replacement therapy (HRT) for women during the menopause is linked to a higher risk of gallbladder problems. A study found that HRT administered by skin patches or gels poses a smaller risk than HRT given orally.
Symptoms of gallstones
The majority of people with gallstones have no symptoms at all. This is because the stones generally stay in the gallbladder and cause no problems. Sometimes, however, gallstones may lead to cholecystitis (inflamed gallbladder).
Common symptoms of gallbladder inflammation include:
- Pain on the right-hand side of the body, just below the ribs
- Back pain
- Pain in the right shoulder
Other possible symptoms:
Biliary colic - Sometimes the gallstones may pass down through the bile duct into the duodenum. When this happens the patient may experience biliary colic - a painful condition. The pain is felt in the upper part of the abdomen, but can also exist in the center of the abdomen, or a little to the right of it. Pain is more common about an hour after eating, especially if the patient has had a high-fat meal. The pain will be constant and will last a few hours, and then subside. Some patients will have non-stop pain for 24 hours, while others may experiences waves of pain.
Infection - If the gallstones have caused a gallbladder infection the patient may have a fever and experience shivering. In the majority of gallstone infection cases the patient will be hospitalized and have the gallstone surgically removed.
Jaundice - If the gallstone leaves the gallbladder and gets stuck in the bile duct it may block the passage of bile into the intestine. The bile will then seep into the bloodstream and the patient will show signs of jaundice - the skin and the whites of the eyes will be yellow. In most cases this complication will require the surgical removal of the gallstone. Some patients are lucky and the gallstone eventually passes into the intestine.
Pancreatitis - If a small gallstone passes through the bile duct and blocks the pancreatic duct, or causes a reflux of liquids and bile into the duct, the patient may develop pancreatitis.
On the next page we look at how gallstones are diagnosed, the available treatments for gallstones and how they can be prevented.