As the name implies, gallstones are hard 'stones' that develop in the gallbladder. They can vary in size from a grain of sand to the size of a ping-pong ball. Gallstones are very common, especially in developed countries, where up to 15% of all adults have them, however only one in three of these people ever have any symptoms. They are more common in women than in men and in people who are overweight. Gallstones can also run in families.


In most cases gallstones do not cause any symptoms at all (in which case no treatment is necessary). They may be discovered on an ultrasound or CT scan performed for a different reason. When symptoms do appear, the most common symptom is severe pain and cramping to the upper abdomen on the right-hand side, which sometimes spreads to the shoulders and the back. The pain can last anywhere from hours to days. Gallstones can sometimes roll out of the gallbladder into the main draining pipe of bile from the liver, the common bile duct, to cause more serious complications such as pancreatitis, jaundice or severe infection in the bile system known as cholangitis.


The function of the gallbladder is to store bile produced by the liver, ready to inject it into the small intestine (duodenum) to assist in the digestion of fat. When a meal is eaten after a period of not eating, bile is sent to the gallbladder in readiness to help this digestion process. Only a small quantity – around 100ml – is stored in the gallbladder, which is 7-10cm in length and sits below the liver. The causes of gallstones are high levels of cholesterol or pigment in the bile. If the gallbladder does not empty fully, the cholesterol in the remaining bile starts to crystallise and then forms into stones. Other causes of gallstones are high levels of a pigment named bilirubin, however this is less common.

Tests & Diagnosis

Gallstones are diagnosed via an ultrasound examination.


As it is very difficult to remove gallstones individually, the commonest approach is to remove the gallbladder entirely in a procedure known as cholecystectomy (otherwise known as gallbladder surgery) The body can function perfectly well without a gallbladder.

Related Information

Gallbladder Surgery