What Are Gallstones?

• Gallstones form in the gallbladder when the balance between the various components of bile becomes disturbed. Increase in concentration of one of these substances causes precipitation of crystals, which gradually accumulate more material and grow into the ‘stones’.
• Gallstones can vary in size from fine sand-like granules to the more common multiple pea-sized stones. In some cases there can be a large single stone that may fill the whole of the gallbladder.
• Around 80% of gallstones are formed from cholesterol and tend to occur when the balance of cholesterol and bile salts is lost or when the gallbladder doesn’t empty properly due to disease. Most of the rest are formed from the bile pigment bilirubin although some contain chalk and some are a mixture of substances.

More information about this condition

• Background information
• Who gets gallstones?
• What causes gallstones?
• Diagnosis of gallbladder disease