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.

See also:

• Acute cholecystitis
• Choledocholithiasis

Causes, incidence, and risk factors:

The cause of gallstones varies. There are two main types of gallstones:

• Stones made out of cholesterol. Gallstones made out of cholesterol are by far the most common type. Cholesterol gallstones have nothing to do with the cholesterol levels in the blood.
• Stones made from too much bilirubin in the bile. Bile is a liquid made in the liver that helps the body digest fats. Bile is made up of water, cholesterol, bile salts, and other chemicals, such as bilirubin. Such stones are called pigment stones.

Gallstones are more common in women, Native Americans and other ethnic groups, and people over age 40. Gallstones may also run in families.

The following also make you more likely to develop gallstones:

• Failure of the gallbladder to empty bile properly (this is more likely to happen during pregnancy)
• Medical conditions that cause the liver to make too much bilirubin, such as chronic hemolytic anemia, including sickle cell anemia
• Liver cirrhosis and biliary tract infections (pigmented stones)
• Diabetes
• Bone marrow or solid organ transplant
• Rapid weight loss, particularly eating a very low-calorie diet
• Receiving nutrition through a vein for a long period of time (intravenous feedings)