Gallstones are lumps of rock-like material that form inside the gallbladder.
Scientists are just beginning to learn what causes gallstones to form. Gallstones may be as small as tiny specks or as large as the gallbladder itself. Gallstone type is important since cholesterol stones are more likely to respond to nonsurgical treatment. Studies have shown that these silent stones do not need to be treated. This is because the initial symptoms are usually mild and experts feel that the risk from surgical removal of the gallbladder is greater than the risk from not treating these silent stones.