Gallstones: Causes

What causes gallstones?

In most cases, gallstones are caused by excessive amounts of cholesterol in the bile that is stored in the gallbladder. The cholesterol hardens to form stone-like substances. The presence of a stone or multiple stones in the gallbladder is known as cholelithiasis. Increased body weight and older age are associated with increased levels of cholesterol in the bile. Thus, gallstones are more likely to occur in women, in people who are obese, and in older individuals.

Some gallstones develop because the bile contains too much bilirubin, a waste product of the liver that is a component of bile. Gallstones that develop from excess bilirubin are called pigment stones.

What are the risk factors for gallstones?

A number of factors increase your risk of developing gallstones. Not all people with risk factors will get gallstones. Risk factors for gallstones include:

• Age over 40 years
• Crash dieting or losing weight rapidly (bile then contains more cholesterol)
• Diabetes
• Ethnicity (risk is higher in American Indians and Mexican Americans)
• Family history
• Female gender
• Liver disease
• Overweight or obesity
• Pregnancy (decreases the gallbladder’s ability to empty bile)
• Use of certain medications (cholesterol-lowering drugs increase cholesterol in the bile)

Reducing your risk of gallstones

Although some risk factors, such as age or gender, cannot be modified, you may be able to lower your risk of gallstones through lifestyle changes including:

• Eating a healthy diet
• Getting regular physical activity
• Losing weight slowly
• Maintaining a healthy weight