Gallstones are crystal-like particles that form in the gallbladder when certain substances separate out of bile. Gallstones can vary dramatically in size, and although some may cause no symptoms, others may lead to serious medical concerns, including inflammation and infection.

What Does the Gallbladder Do?

The gallbladder is a small, pear-shaped organ that sits under the liver on the right side of the abdomen * . The gallbladder concentrates and stores the greenish-brown liquid called bile, a digestive juice that is made by the liver. When a person eats food, the gallbladder contracts and sends bile through tubes called bile ducts and into the small intestine, where it helps break down fats in the food.

Bile has a number of ingredients, including water and dissolved bile salts. Bile salts act like detergent and help dissolve globules of fat. Bile also contains the following:

Like the bile salts, these substances are usually completely dissolved in the bile. When an imbalance exists, however, gallstones can develop. For instance, too much cholesterol can cause the bile to form crystals that drop out of the liquid. These crystals are gallstones.

The gallbladder sits under the liver on the right side of the abdomen near the pancreas. When gallstones are formed, they can block the bile ducts, leading to pain and damage to the gallbladder, liver, and pancreas.

The gallbladder sits under the liver on the right side of the abdomen near the pancreas. When gallstones are formed, they can block the bile ducts, leading to pain and damage to the gallbladder, liver, and pancreas.
Illustration by Frank Forney. © 2016 Cengage Learning®.

What Are Gallstones?

Gallstones are pieces of solidified bile. The components of bile usually remain dissolved, but when something goes wrong that upsets the normal chemical balance, gallstones can form. Gallstones come in two main types: cholesterol stones, which account for about 80 percent of gallstones in the United States, and pigment stones, which form from bilirubin and calcium, a mineral that is also found in bile.

Gallstones can develop when a chemical imbalance exists in the bile, which causes it to contain more cholesterol (or bilirubin and calcium) than can be dissolved, or when the gallbladder does not contract enough to empty itself of bile on a regular basis. Gallstones can range in size from gravel-like particles to spheres the size of golf balls. Some people have single stones, whereas others develop many stones.

Who Is at Risk for Gallstones?

One in every 10 people in the United States, or about 30 million people, have gallstones. Gallstones are rare in children and adolescents, but anyone can get them.


Diets high in cholesterol seem to be linked to gallstones, although some researchers believe that a high cholesterol diet must be accompanied by a genetic predisposition * toward gallstones. Anything that increases the cholesterol level in bile, including pregnancy, hormone therapy, and birth control pills, can increase a person's susceptibility to getting cholesterol stones.

Obesity and other health conditions

Obese people also have a higher risk of gallstones, as do people who are fasting or on fad diets. Dieters may develop stones because lack of food means that the gallbladder does not regularly contract to release its bile, and the bile may sit in the gallbladder for a long time. People with liver diseases, infections of the bile ducts, and blood cell disorders (such as sickle cell anemia * ) are prone to developing pigment stones.

Other populations

Groups of people who also seem to be at higher risk of developing gallstones include the following:

What Happens When People Have Gallstones?

Most gallstones do not cause symptoms; only one in five people with gallstones experiences problems.

Symptoms Diagnosis

Medical professionals usually only diagnose gallstones if they are causing problems. To look for gallstones, doctors may use x-rays and ultrasound, a painless procedure in which sound waves passing through the body create images on a computer screen.


The standard treatment for gallstones, and the only one guaranteed to cure gallstones permanently, is surgical removal of the gallbladder, usually through laparoscopic surgery (surgery performed through tubes that are inserted into the abdomen through small incisions). Doctors perform more than 700,000 of these operations every year in the United States. If a person cannot have laparoscopic surgery, the doctor may remove the gallbladder through an open incision 5 to 8 inches long in the abdomen.

People who cannot have surgery or do not want to have surgery can take medication to help dissolve gallstones, although this process can take months or even years. They may also undergo lithotripsy (LITH-o-tripsee). In this procedure, shock waves pass through the skin to shatter the stone into tiny particles that may be able to pass out of the gallbladder on their own.

See also Eating Disorders: Overview • Gallbladder Disease • Jaundice • Obesity • Pancreatitis • Pregnancy


Books and Articles

Reller, Paul, L. “Gallstone Prevention.” Acupuncture Integrated. June 07, 2015. (accessed October 21, 2015).


National Institute of Diabetes and Digestive and Kidney Diseases. 9000 Rockville Pk., Bethesda, MD 20892-2560. Telephone: 301-496-3583. Website: (accessed July 26, 2016).


American Gastroenterological Association. 4930 Del Ray Ave., Bethesda, MD 20814. Telephone: 301-654-2055. Website: (accessed October 21, 2015).

* abdomen (AB-do-men), commonly called the belly, is the portion of the body between the thorax (THOR-aks) and the pelvis.

* genetic predisposition is an inherited tendency to get a certain disease.

* sickle cell anemia, also called sickle cell disease, is a hereditary condition in which the red blood cells, which are usually round, take on an abnormal crescent shape and have a decreased ability to carry oxygen throughout the body.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)