The gallbladder is a small pouch that sits just under the liver. The gallbladder stores bile produced by the liver. After meals, the gallbladder is empty and flat, like a deflated balloon. Before a meal, the gallbladder may be full of bile and about the size of a small pear.
In response to signals, the gallbladder squeezes stored bile into the small intestine through a series of tubes called ducts. Bile helps digest fats, but the gallbladder itself is not essential. Removing the gallbladder in an otherwise healthy individual typically causes no observable problems with health or digestion yet there may be a small risk of diarrhea and fat malabsorption.
Gallstones (cholelithiasis): For unclear reasons, substances in bile can crystallize in the gallbladder, forming gallstones. Common and usually harmless, gallstones can sometimes cause pain, nausea, or inflammation.
Cholecystitis: Inflammation of the gallbladder, often due to a gallstone in the gallbladder. Cholecystitis causes severe pain and fever, and can require surgery when inflammation continues or recurs.
Gallbladder cancer: Although rare, cancer can affect the gallbladder. It is difficult to diagnose and usually found at late stages when symptoms appear. Symptoms may resemble those of gallstones.
Gallstone pancreatitis: An impacted gallstone blocks the ducts that drain the pancreas. Inflammation of the pancreas results in a serious condition.