Gall stones, basically, are clusters of cholesterol crystals, and they form within the gall bladder very similar to how a pearl forms in an oyster. Those cholesterol clusters get together and form bigger stones, and for the most part, these stones never cause any problems. The only time they cause problems is if they get stuck in the duct that empties the gall bladder. People who get gall stones are mostly women that are obese, that are around age 40, are of Mexican-American descent or Native American descent. It also has a higher incidence of forming in pregnant women, also, because the hormonal shifts cause the gall bladder to be very sluggish, and they have an increased incidence of forming gall stones. The gall bladder, basically, is a purse that holds the bile, which is a chemical that we make in order to help digest fat.