Gallbladder disease is usually caused by gallstones. Gallstones start to form when cholesterol, calcium and phosphate crystallize in the bile. These crystals continue to grow to form stones.

Bile is made by the liver, and stored in the gallbladder. The gallbladder pushes bile into the intestine through the bile duct. In the intestine, the bile helps digest food. Gallstones can become large enough to obstruct the bile duct. Once the bile duct is obstructed, the gallbladder becomes swollen and inflamed, and causes symptoms.