Gallstones Patient Information Fact Sheet

What are gallstones?
The presence of stones in the gallbladder is known as cholelithiasis. There are two types of gallstones: cholesterol stones and bile pigment stones. Cholesterol stones can be pure or mixed (also containing calcium salts and protein) and are the most common types of gallstones. Bile pigment stones can be black (pure) or brown (also containing cholesterol). Black bile pigment stones are hard and brittle while brown stones are soft and crumbly. The number and size of gallstones present can vary enormously from one large stone to several thousand tiny stones (like gravel).

Gallstones affect around 10–20% of the world’s population. They are more prevalent in industrialized countries probably as a result of dietary factors, and are rarely found in less developed countries. Although it is possible to develop gallstones at an early age, this is extremely rare. The incidence of gallstones increases with age. Women are more prone to gallstones than men, although pure bile pigment stones affect both sexes equally. 

What causes gallstones?
Although diet is often blamed for causing gallstones, this has not been proven. In fact, not eating for long periods can exacerbate the problem. Bile pigment gallstones may arise in children with hemolytic anemia. In this condition, a larger than usual amount of bilirubin from the blood is broken down and passed into the bile, causing the formation of the stones.

Gallstones can run in families, but they are so common within the general population that this may not be relevant.

What are the symptoms of gallstones?
In most cases, gallstones remain in the gall bladder where they may not cause any problems. Many patients will not have any symptoms and as a result will be unaware that they have gallstones. The main symptom caused by gallstones is biliary colic. This is a severe pain that can start at any time and is often worse on the right side of the upper abdomen. It may last for hours before it fades. It can also cause vomiting. Cholecystitis is an acute (develops suddenly and lasts a short time) or chronic (develops gradually and lasts a long time) inflammation of the gallbladder thought to occur when a gallstone becomes stuck in the bile duct (a tube leading from the gall bladder to the intestine). Cholecystitis causes pain and if an infection develops, the patient will also have a fever.