Gallstones are small, hard pellets that form in the gallbladder. They can block the bile duct, which transports bile from the liver to the small intestine. The major symptom of gallstones is severe pain.

Bile is a mixture of compounds, including cholesterol, that aids digestion by breaking globs of fat in the intestine into tiny droplets, which can then be absorbed into the blood stream. The liver makes bile and stores it in the gallbladder.

There are two major varieties of gallstones: those composed primarily of cholesterol and those made of various pigments derived from hemoglobin, the oxygen-carrying substance of red blood cells. About 80 percent of the gallstones in the United States are the cholesterol variety. They form when bile contains too much cholesterol; the cholesterol then solidifies to form stones.

About 10 percent of all adults in the United States have gallstones. Women are twice as likely as men to develop them. Native Americans are particularly prone to gallstones, with as much as 65 percent of some groups suffering from this disease.

Obesity increases the risk of gallstones by increasing cholesterol secretion into bile. It seems logical that a high cholesterol intake would increase cholesterol secretion into the bile and increase the risk of gallstones, but there is no firm evidence from studies in humans that the concentration of cholesterol in bile is increased by high intakes of cholesterol.


The liver is susceptible to injury from a variety of causes. Cirrhosis of the liver is a chronic disease whose relentless progression destroys normal liver structure and function. Eventually, the liver fails and death results. Cirrhosis may be caused by viral hepatitis, hemachromatosis (a disease in which excess iron accumulates in the liver), obstruction of the biliary system,

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement