How big can gallbladder stones get?

Gallbladder stones, or gallstones, can grow as large as a golf ball, according to the National Institute of Diabetes and Digestive and Kidney Diseases. The gallbladder can form many small, sand-grain-sized gallstones, one large gallstone or a combination of large and small stones.

Gallstones form when the components of gallbladder bile are out of balance, explains the National Institute of Diabetes and Digestive and Kidney Diseases. Potential gallstone-causing imbalances include an overabundance of cholesterol, too much bilirubin or a shortage of bile salts. Additionally, gallstones can form if the gallbladder does not empty thoroughly or frequently enough. Gallstones can cause immediate pain in the upper-right abdomen as they block the biliary tract ducts.