The gallbladder stores bile, a fluid which is released into the small intestine where it emulsifies fats and assists their digestion. Over 80 percent of gallstones are composed of solid cholesterol; the rest is solid bilirubin (the main pigment found in bile). Gallstones are usually diagnosed by ultrasound, but other procedures such as X-rays may also be used.
About 80 percent of people who have gallstones have no symptoms (non-symptomatic gallstones). However, in a minority of cases, gallstones trigger severe abdominal pain (symptomatic gallstones). In these instances, the gallstones can cause the gallbladder to become inflamed and this leads to gallbladder disease.
Across Europe, studies have shown that gallstones affect between 6-22% of the population1.
In the US, it is estimated that over 20 million individuals have gallbladder disease2. Even though gallbladder disease has a low mortality rate of 0.6%, considering how common gallstones are, there were still an estimated 1092 gallstone-related deaths in 20043 in the US. However, gallstone-related deaths have steadily declined from more than 5000 deaths in 1950, falling more than 50% between 1979 and 2004, representing the greatest decrease for any digestive disease in the US3.