(HealthDay News) -- Gallstones are hard pieces that form in the gallbladder when substances such as bilirubin and cholesterol crystallize inside the muscular sac that's attached to the liver.
The American Gastroenterological Association says while it's not understood why some people develop gallstones and others don't, the following factors increase a person's risk:
- Being obese
- Not getting enough exercise.
- Being female.
- Having high amounts of cholesterol or bilirubin in the bile.
- Being older than age 40.
- Having diabetes or liver disease.
- Having a family history of gallstones.
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