Anatomy of a Gallstone
all information

Anatomy of a Gallstone

Could you have a gallstone, but not know it? Usually lying dormant for years, they can be extremely painful, even dangerous, if they become symptomatic. John H., an overweight, 55-year-old accountant, woke up one morning not long ago with terrible pains in his upper abdomen and right shoulder. Positive he was having a heart attack, he rushed off to the emergency room. But alas, John's problem was far less dramatic and, fortunately, less critical. Gallstones.


To understand gallstones, an anatomy lesson is helpful. The gallbladder is a small, pear-shaped organ that is part of the digestive system. Located on the right side of the abdomen below your liver, the gallbladder stores and secretes bile (made by the liver) into your small intestine when food arrives there from your stomach. Bile, a yellow-brownish fluid, helps digest fats in food.

Gallstones form when substances in the bile crystallize, or harden. There are two types of gallstones:

  • Cholesterol gallstones—Made mostly of cholesterol, these yellow-green stones comprise about 80% of gallstones.
  • Pigment gallstones—Made mostly of bilirubin and calcium salts, these smaller and darker stones account for the remaining 20% of gallstones.

Gallstones can be as small as a grain of sand, or as large as a golf ball (though smaller gallstones are much more common). Some people will develop only one or a few larger gallstones, while others can develop hundreds of smaller ones.

What Causes Gallstones?

Though scientists do not yet understand exactly how gallstones occur, a number of factors are known to contribute to their formation:

  • Body chemistry—This happens when the bile contains too high a concentration of cholesterol and too low a concentration of bile salts.
  • Efficiency—This is how efficient your gallbladder is at contracting and flushing bile into the intestine.
  • Proteins—Improper balance of different types of proteins in the liver or bile may make you more susceptible to gallstones.
  • Obesity—Being overweight may make you more susceptible to gallstones, probably because it exacerbates the factors listed above.
  • Weight loss—The process of losing weight (especially losing weight rapidly) may also make you more susceptible to gallstones, again probably because it exacerbates the factors listed above. (Note: Virtually all medical professionals agree that gradual weight loss is highly beneficial to your health, even if it may raise your susceptibility to gallstones.)
  • Estrogen levels—In women, increased estrogen levels due to pregnancy, birth control pills, or hormone therapy may increase the risk of gallstones.

What Does It Feel Like to Have Gallstones?

As noted, people who develop gallstones generally do not experience any symptoms for years, and many never develop symptoms. However, if you do experience a gallstone attack, the symptoms can be severe, and sometimes dangerous. Usually experienced as severe pain in the upper abdomen, upper back between the shoulder blades, or right shoulder, gallstone attacks can last anywhere from 20 minutes to a number of hours, and are often accompanied by nausea and vomiting. Once they occur, attacks may recur very frequently (weeks or months apart) or infrequently (a year or years apart). If you do experience a gallstone attack, you're likely to have another at some point.

Although very painful, gallstone attacks are usually not life-threatening as long as the gallstones remain in the gallbladder. However, if the gallstones migrate out of the gallbladder, serious problems can develop:

  • If gallstones migrate and block the duct draining the gallbladder into the small intestine, cholecystitis (inflammation of the gallbladder) can result.
  • If gallstones migrate and block the main duct between the liver and the intestine, jaundice (yellowing of the skin) and/or pancreatitis (inflammation of the pancreas) can result.

If these complications do develop, and are left untreated, they can be fatal.

How Are Gallstones Diagnosed?

Since gallstones without symptoms are seldom treated, doctors rarely test for them. However, when symptoms do occur and gallstones are suspected, an ultrasound is generally done. These devices send sound waves into the abdomen, and if gallstones are present, the waves will bounce back, showing the location of the stones and creating an image of them.

Gallstone Treatment Options

Once gallstones become symptomatic and are diagnosed, they can be treated in a number of ways.


One treatment for gallstones is a cholecystectomy surgery to remove the gallbladder. This can be done as an open surgery (a large incision is made into the abdomen to remove the gallbladder) or as a laparoscopic surgery. For laparoscopic surgery, small incisions are made in the abdomen, and a small camera and surgical tools are then passed through these incisions. Watching on a TV monitor, the surgeon removes the gallbladder, and stitches the internal and external incisions.

Like open surgery, a laparoscopic cholecystectomy is done under general anesthesia. However, unlike open surgery, the laparoscopic method requires only small incisions, and no cutting of abdominal muscles. As a result, the laparoscopic method causes much less postoperative pain than open surgery, as well as less days in the hospital (overnight compared to several days) and less recuperation time (a few days compared to at least a week).

Nonsurgical Methods

There are also nonsurgical methods available to treat gallstones.

In oral dissolution therapy you would be asked to take medicines made from bile acids to dissolve gallstones. Generally lasting anywhere from a few months to a few years, this therapy is usually only prescribed for those with very small, cholesterol-type gallstones, since people with large gallstones often suffer recurrence of symptoms after this therapy.

Contact dissolution therapy involves introducing and removing a gallstone-dissolving agent into the gallbladder through a catheter that is attached to a pump. This type of gallstone treatment is generally experimental.

Who Should Be Tested for Gallstones?

In the absence of symptoms, there is generally little purpose for the average person to be tested for gallstones since they are usually not treated unless they become symptomatic. However, if you do experience the type of pain common to gallstones described above, then you should be tested. In addition, if you show evidence of jaundice or any trouble with your pancreas, you should seek medical attention immediately, which should include testing for gallstones.

Are you likely to get gallstones? Anyone can develop them, however, those most susceptible are:

  • Women, especially those who are pregnant, use birth control pills, or receive estrogen replacement hormone therapy (women are twice as likely to develop gallstones as men)
  • Native Americans and Mexican Americans
  • Men and women who are over age 60
  • People who are overweight
  • People who diet, especially those who diet frequently and/or who lose weight quickly (either due to diet or other causes, such as illness or non-gallstone-related surgery)
  • People who experienced rapid weight loss or fasting
  • People with diabetes
  • People who are taking cholesterol-lowering drugs

Life Without a Gallbladder

Can you live without your gallbladder? Yes. The gallbladder simply functions as a storage area for bile, squirting bile into the small intestines when we eat to help digest the food. Without a gallbladder, bile simply drains directly into the small intestines from the liver at a steady rate all day. But side effects of not having a gallbladder may include increased instances of diarrhea.

Persons with gallstones that are not causing symptoms need to carefully weigh the risks of gallbladder removal surgery against potential complications that could occur if the gallbladder is not removed. These complications include eventually developing a painful complication of gallstones. Talk with your doctor to learn more.


American Liver Foundation

National Digestive Disease Information Clearinghouse


Canadian Liver Foundation

Health Canada


Gallstones. National Digestive Disease Information Clearinghouse website. Available at: Updated July 2007. Accessed June 6, 2011.

Last reviewed June 2011 by Brian Randall, MD

Last updated Updated: 6/6/2011

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

Your Health and Happiness