The symptoms of gallbladder stones depend on the size and location of the stones, as well as the presence of obstruction and inflammation. About 50% of patients with gallbladder stones are asymptomatic for life, known as occult stones. Larger gallbladder stones may cause symptoms of indigestion such as stuffiness and distension in the upper or right side of the abdomen, belching and aversion to fatty foods. Smaller stones may cause biliary colic and acute cholecystitis when they obstruct the gallbladder duct after a full meal, eating fatty foods, or lying down at night. Due to the contraction of the gallbladder, smaller stones may pass through the cystic duct into the common bile duct and cause obstructive jaundice, and then some stones may be discharged from the bile duct into the duodenum, while some stones remain in the bile duct and become secondary bile duct stones. Stones may also obstruct the bile duct for a long time without infection and only form a fluid in the gallbladder, at which time an enlarged gallbladder without obvious pressure can be palpated. When gallbladder stones are not infected, there are usually no specific signs or only mild pressure pain in the right upper abdomen. However, when there is an acute infection, pressure pain and muscle tension in the middle and upper right abdomen may occur, and sometimes an enlarged and painful gallbladder may be palpated.