Gallstones are solid pieces that form in the gallbladder, which is a small sac-like organ located beneath the liver. The gallbladder stores bile, a substance produced by the liver that helps in breaking down fats during digestion. Gallstones are made up of cholesterol, bile salts, and calcium deposits. They can vary in size, from as small as a grain of sand to as big as a golf ball.

Gallstones usually form when there is too much cholesterol or other substances in the bile, causing it to harden and form solid masses. They can also develop when the gallbladder doesn’t empty properly, allowing the bile to become concentrated. Gallstones can block the flow of bile, leading to symptoms such as abdominal pain, nausea, and vomiting.

In some cases, gallstones can be treated with medications that help dissolve them. However, if the gallstones are causing severe symptoms or complications, surgery may be required to remove the gallbladder (cholecystectomy). The gallbladder isn’t essential for survival, and the body can still digest fats without it.