Gallstones are hardened pieces of material that form in the gallbladder, explains WebMD. Typically, gallstones are comprised of either cholesterol or pigments. They are caused by genetics, obesity, hormonal imbalances and diet.
Gallstones range in size, with some being as small as a grain of sand and others being the size of a golf ball, states Mayo Clinic. Gallstones and the gallbladder are typically removed only if a patient experiences symptoms. Symptoms of gallstones include pain in the upper abdomen, nausea, vomiting, abdominal bloating and heartburn, according to WebMD.
The gallbladder is a digestive organ that secretes a substance called bile into the small intestines, describes WebMD. When there is an imbalance of the substances that form bile, gallstones tend to form. Those with family members who have had gallstones are at a higher risk of developing them. Women who are pregnant or taking birth control pills are also prone to gallstones, since they tend to have higher levels of estrogen, which can inhibit the movement of bile out of the gallbladder. If a person loses weight too rapidly or fasts for an extended period of time, the liver secretes excess cholesterol, which can contribute to the formation of gallstones.