Causes and Risk Factors

Bile, or the greenish-brown fluid that is made of bile salts, fatty compounds, cholesterol, and other elements, is produced by the liver to aid in digesting fat in the small intestine. Bile is concentrated and stored in the gallbladder, which eventually releases bile to aid in the digestive process. A chemical imbalance of bile causes gallstones to form that may vary in size and in number.

As mentioned earlier, there are two types of gallstones: cholesterol gallstones and pigment gallstones. A high cholesterol level in the bile of an individual, which is not related to a high cholesterol level in the blood stream, is one of the causes of gallstone formation. Incomplete or infrequent emptying of the gallbladder leads to a high concentration of bile and eventually contributes to the formation of gallstones. This may occur because of several factors including maintenance of a very low-calorie diet, skipping meals, rapid weight loss, and pregnancy. Females, people over the age of 40, and those who are overweight are more likely to develop gallstones. The condition also seems to be more prevalent among the individuals of Asian and European origin.