The gallbladder lies beneath the liver: a pear-shaped pouch in which bile collects. During a meal, the gallbladder contracts and releases the fluid into the intestine, where it makes fat digestible. If the bile contains more cholesterol than it can keep dissolved, crystals form – and over the years, these can grow into stones.
Women are affected more often than men, and the risk increases with age, with excess weight and with a family tendency. Rapid weight loss, for example after obesity surgery, also favours stones. Most people who have them notice nothing: the stones are discovered by chance on ultrasound and, as long as they stay quiet, are simply monitored.
If a stone becomes lodged in the outlet of the gallbladder, the organ contracts in spasms. This biliary colic causes severe, wave-like pain in the right upper abdomen, often radiates to the back or shoulder and typically begins after a fatty meal, usually accompanied by nausea. A first episode of colic is often followed by more.
Warning signs are fever, pain that does not ease, and yellow skin or yellowish eyes, often together with dark urine and pale stools. This may point to an inflamed gallbladder or a stone blocking the bile duct – which should be checked by a doctor the same day.