What Is the Gallbladder's Function?
Medically reviewed by Jay N. Yepuri, MD
The gallbladder is a small, pear-shaped organ located on the right side of your abdomen, just beneath your liver. It plays a key role in digestion. The gallbladder's main function is to store bile, a liquid produced by your liver that helps digest fat. When you eat, your gallbladder releases bile into your small intestine. Meals with a higher fat content require more bile.
Many issues can result from a dysfunctional gallbladder, and many conditions can affect it. The most common cause of dysfunction is a blockage that reduces bile flow. In more severe cases, your gallbladder might be removed because your body can function without it.
Gallbladder-related conditions include gallstones (tiny stone-like objects composed of hardened bile material), cholecystitis (inflammation), and cancer.
Illustration by Dennis Madamba for Health
Anatomy of the Gallbladder
The gallbladder is a small organ in your upper right abdomen.
Structure
The gallbladder is about one inch wide and 3-4 inches long. There are three main parts:
Fundus: The large end that stores bile
Body: Where the gallbladder begins to taper, becoming narrower
Neck: Where the gallbladder tapers further and connects to the cystic duct, a tube that leads to the common hepatic duct just outside the liver
The cystic duct and the gallbladder typically meet at an area called Hartmann’s Pouch. This is the area where gallstones can potentially get stuck. The gallbladder also contains what is known as spiral valves of Heister. These valves may promote gallbladder emptying through neural (nerve) and hormonal stimulation.
The gallbladder has multiple layers, including:
Epithelium: A thin layer of cells that line the inner wall
Lamina propia: A thin layer of connective tissue that, with the epithelium, forms the inner layer called the mucosa
Muscularis: A layer of muscle that helps the gallbladder contract and move bile into the bile ducts (tubular structures that carries bile to the small intestine)
Perimuscular tissue: Tissue around the muscularis
Serosa: The smooth, outermost layer
Location
Your gallbladder is located on the right side of your abdomen, just below your liver. It's connected to your digestive system by a system of hollow ducts called the biliary system.
What is the biliary system?
The biliary system, also known as the biliary tract, includes the gallbladder as well as bile ducts inside and outside of the liver. It produces, transports, and stores bile. It also carries waste products from your liver to your duodenum (the first section of your small intestine).
Anatomical Variations
Congenital (from birth) gallbladder abnormalities are rare, but they include:
Agenesis: Absence of a gallbladder
Hypoplasia: An underdeveloped gallbladder
Left-sided gallbladder: A condition in which the gallbladder moves to the left side of the liver or a second gallbladder develops and the original gallbladder becomes smaller
What Does the Gallbladder Do?
The gallbladder plays a key role in digestion because it stores and concentrates bile. Your liver produces about 27-34 fluid ounces (oz) of bile daily. Your gallbladder can store 30-50 milliliters (mL) of it.
Your body doesn't need to digest fat unless you're eating. When you're not eating, or fasting, about 75% of bile goes to your gallbladder for storage until it's needed. Your gallbladder makes the bile more concentrated by absorbing most of the water.
When you eat, the bile produced by your liver flows directly into your small intestine. If you eat food that contains fat, your stomach and small intestine release cholecystokinin (CCK), a hormone that causes your gallbladder to contract. This squeezes 50-75% of its stored bile into your small intestine. This bile emulsifies (breaks down) the fat, which helps your body use it for energy.
What is bile?
Bile is a greenish-brown fluid that helps break down fats. It's made primarily of water, but it also contains bile salts, cholesterol, certain fats (like lecithin), and bile pigments. Bilirubin is the most important bile pigment. It's what makes urine yellow and stool brown.
Associated Conditions
A number of conditions can affect your gallbladder. The most common condition is gallbladder disease, which includes inflammation, infection, gallstones, or a blockage in the gallbladder. Gallbladder cancer is rare.
Here are some gallbladder-related conditions:
Cholelithiasis (gallstones): Gallstones are small, hardened deposits that form in your gallbladder and can go undetected for years. They are generally composed of cholesterol, bilirubin, and bile. Most people with gallstones are asymptomatic, meaning they have no symptoms. In the United States, about 20 million people between the ages of 20 to 74 have gallstones. Symptoms include sharp abdominal pain, fever, and nausea.
Cholecystitis: This condition occurs when inflammation impairs the emptying of the gallbladder. It can be acute or chronic. Symptoms of acute cholecystitis are often more severe. People typically develop cholecystitis when they have gallstones, but it can also result from an infection.
Porcelain gallbladder: Calcium deposits can stiffen gallbladder walls and cause the gallbladder to become rigid. This calcification is rare and typically occurs in people above the age of 60 who have gallstones. Gallstones are present in 60-90% of cases.
Choledocholithiasis: This condition occurs when gallstones form in the common bile duct (CBD), a tubular structure that carries bile from the gallbladder to the small intestine. CBD stones are present in less than 15% of people with gallstones.
Gallbladder empyema: This condition involves a collection of pus in the gallbladder. It's the most severe complication of acute cholecystitis and occurs in 5-15% of cases. Empyema usually requires emergency surgery and prompt treatment with antibiotics to reduce the risk of septic shock (dangerously low blood pressure after an infection).
Gallstone ileus: A gallstone will sometimes travel into the intestine and cause a blockage. Without prompt treatment, this condition can be fatal.
Gallbladder cancer: This type of cancer is rare and difficult to diagnose. It occurs when malignant cells are found in gallbladder tissue.
Related: Gallbladder Problems: Everything You Need To Know
Diagnostic Testing
Your healthcare provider may conduct a number of different tests to diagnose a gallbladder issue. You'll likely work with a gastroenterologist, a medical doctor who specializes in the digestive system.
Diagnostic tools might include:
Blood tests: Your healthcare provider will likely order bloodwork if they suspect an issue with your gallbladder. The results can help diagnose an infection or inflammation. They may look at your bilirubin levels. Bilirubin is a yellowish substance in bile that can be toxic. Hyperbilirubinemia (high bilirubin levels) can lead to side effects like jaundice, a yellowish discoloration of skin and eyes.
Abdominal ultrasound: An ultrasound is a noninvasive test that uses sound waves to view your gallbladder and surrounding areas. It's the preferred test for finding gallstones.
Hepatobiliary nuclear medicine: Also called a hepatobiliary iminodiacetic acid (HIDA) scan or cholescintigraphy, this test uses radioactive material to produce pictures of your biliary tract. During the test, pictures will be taken as the radioactive material moves through your biliary tract.
Magnetic resonance cholangiopancreatography (MRCP): The MRCP is a specialized form of magnetic resonance imaging (MRI) that does not use radiation. It produces detailed images of your liver, gallbladder, bile ducts, pancreas, and pancreatic duct.
Endoscopic ultrasonography (EUS): This test provides detailed images of your digestive tract. It can provide high-resolution images and may be used when other tests are inconclusive or conflicting.
Endoscopic retrograde cholangiopancreatography (ERCP): This procedure uses an endoscope (a thin, flexible, lighted tube with a camera) and a catheter (a thin, flexible tube) to x-ray the ducts that carry bile from your liver to your gallbladder and from your gallbladder to your small intestine.
Percutaneous transhepatic cholangiography (PTC): A thin needle is inserted through your skin below your ribs and into your liver. A dye is injected and an x-ray is taken.
Tips for Keeping Your Gallbladder Healthy
Gallbladder disease can cause extreme pain or even life-threatening complications, but you can take steps to help keep your gallbladder healthy. Your gallbladder is part of your digestive system, so gallbladder health often revolves around diet.
Here are some common food recommendations:
Prioritize high-fiber foods: Foods like fruits, vegetables, beans, and whole grains contain many important nutrients like vitamin C, folate, and magnesium, all of which have been linked to a lower risk of gallbladder disease. They also contain fiber, which can help prevent gallstones.
Eat healthy fats: Foods that contain healthy fats—including fish, fish oil, and nuts—help your gallbladder function effectively.
Limit fast food and refined sugar: Eating these foods regularly might increase your risk of gallbladder disease.
Eat frequently: Your liver releases extra cholesterol into the bile when you don’t eat for a long period of time. Eating frequently and avoiding prolonged fasting helps the gallbladder empty regularly, which can prevent gallstones.
Rapid weight loss can increase your risk of gallbladder disease. Your liver releases extra cholesterol into the bile when you lose weight quickly. This could lead to the development of gallstones. Rapid weight loss may also cause your gallbladder to empty ineffectively.
Reach out to your healthcare provider if you have a medical condition that causes you to lose weight rapidly or if you're considering weight loss surgery. They can help prevent possible gallbladder issues. For example, a medication called ursodiol (brand names include Actigall and Urso Forte) can help prevent gallstones.
Related: Best Foods for Your Gallbladder
A Quick Review
Your gallbladder is a small pear-shaped organ located just below your liver. It's responsible for storing and concentrating bile and moving it into your small intestine when needed for digestion.
A number of conditions can affect your gallbladder including gallstones and cholecystitis. Your healthcare provider may order a number of different tests, including bloodwork and imaging tests, if they suspect an issue.
You can support gallbladder health by limiting fast food and refined sugars and consuming high-fiber foods and healthy fats. You can also be mindful of weight loss. Reach out to your healthcare provider if you suspect a possible gallbladder issue.
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