Dr Pallavi Ajankar is the Best Gallbladder Surgeon/Gallstone Surgeon in Kasarvadavali, Naupada, Thane West and Thane. Gallstones are hardened deposits of cholesterol or bilirubin that form in the gallbladder, a small organ under the liver that stores bile. Most gallstones are painless and require no treatment, but if they block the bile ducts, they can cause sudden, severe pain (biliary colic) and lead to complications like infection or inflammation, requiring medical attention and often surgical removal of the gallbladder. Causes and formation- • Composition: Gallstones are made of hardened cholesterol or bilirubin that precipitates out of bile. • Improper emptying: They can form when the gallbladder doesn't empty properly or when the liver produces too much bilirubin. • Cholesterol imbalance: They can also form when bile contains too much cholesterol, or when there are not enough bile salts to keep it dissolved. • Stasis: Gallbladder inactivity or “stasis” can also cause cholesterol to separate and form solids.