Definition of Gallstones:

Gallstones are hard, pebble-like deposits that form inside the gallbladder. Gallstones may be as small as a grain of sand or as large as a golf ball, depending on how long they have been forming.

Causes, incidence, and risk factors:

The cause of gallstones varies. Some stones form when there is too much cholesterol or bilirubin in the bile. (Bile is a liquid that helps the body digest fats.) Other stones form if there are not enough bile salts or if the gallbladder fails to empty properly.

One type of gallstones, called pigment stones, tend to occur in people who have medical conditions that cause the liver to make too much bilirubin. Pigment stones are also more common in persons with liver cirrhosis and biliary tract infections.

Gallstones are a common health problem worldwide. They are more common in women, Native Americans, and people over the age of 40.

Other risk factors include ethnic and genetic factors, obesity, diabetes, cirrhosis, receiving nutrition through a vein for a long period of time (intravenous feedings), and certain operations for peptic ulcers.