Your gallbladder is one of those organs that you probably don’t think too much about — unless something goes wrong.
What Is the Gallbladder?
The gallbladder is a pear-shaped, hollow structure located under the liver and on the right side of the abdomen. Its primary function is to store and concentrate bile, a yellow-brown digestive enzyme produced by the liver. The gallbladder is part of the biliary tract.
The gallbladder is a small pouch that sits just under the liver. The gallbladder stores bile produced by the liver. After meals, the gallbladder is empty and flat, like a deflated balloon. Before a meal, the gallbladder may be full of bile and about the size of a small pear.
The gallbladder serves as a reservoir for bile while it’s not being used for digestion. The gallbladder’s absorbent lining concentrates the stored bile. When food enters the small intestine, a hormone called cholecystokinin is released, signaling the gallbladder to contract and secrete bile into the small intestine through the common bile duct.
The bile helps the digestive process by breaking up fats. It also drains waste products from the liver into the duodenum, a part of the small intestine.
An excess of cholesterol, bilirubin, or bile salts can cause gallstones to form. Gallstones are generally small, hard deposits inside the gallbladder that are formed when stored bile crystallizes. A person with gallstones will rarely feel any symptoms until the gallstones reach a certain size, or if the gallstone obstructs the bile ducts. Surgical removal of the gallbladder (cholecystectomy) is the most common way to treat gallstones.
In response to signals, the gallbladder squeezes stored bile into the small intestine through a series of tubes called ducts. Bile helps digest fats, but the gallbladder itself is not essential. Removing the gallbladder in an otherwise healthy individual typically causes no observable problems with health or digestion yet there may be a small risk of diarrhea and fat malabsorption.
The gallbladder is an organ that’s found in your abdomen. Its function is to store bile until it’s needed for digestion. When we eat, the gallbladder contracts, or squeezes, to send bile into your digestive tract.
Gallbladder disorders such as gallstones are common digestive conditions. It’s estimated that up to 20 million Americans have gallstones. Keep reading to learn more about the gallbladder, its function, and the signs of a gallbladder problem. Gallbladder problems are usually due to a blockage in your bile ducts, the tubes that let bile travel between your liver, gallbladder, and small intestine. The most common source of blockage is gallstones (cholelithiasis), which develop when substances in bile harden.
Where Is Your Gallbladder Located?
Your gallbladder is located in the right upper quadrant of your abdomen. This is the area on the right side of your abdomen that ranges from the bottom of your sternum (breastbone) to your navel.
The gallbladder is located inferior (below) and posterior (behind) to the liver in the upper right quadrant (section) of the abdomen. It lies in front of the duodenum (the first section of the small intestine). The gallbladder is connected to the liver via the ducts known as the biliary tract.
The gallbladder is attached to the digestive system by a system of hollow ducts called the biliary tree. The gallbladder, bile ducts (tubules in which bile travels through) and associated structures (which are responsible for producing and transporting bile) comprise what is called the “biliary system.” This is sometimes referred to as the biliary tract.
Inside your body, the gallbladder can be found under the liver. It’s approximately the size of a small pear.
Functions of the Gallbladder
The main functions of the gallbladder traditionally were thought to consist of storage and concentration of hepatic bile and ejection of this bile in response to neurohormonal signals. This simplified view of the gallbladder has given way to a more complex and nuanced view of gallbladder function. The contemporary view also includes modification of biliary lipid concentrations and secretion of a variety of proteins that subserve diverse functions that affect not only the gallbladder mucosa itself, but also other gallbladder compartments such as inflammatory and smooth muscle cells. More importantly, an appreciation of the dynamic nature of the relation between the gallbladder and biliary constituents has emerged.
Cholesterol and bile salts are actively transported by the gallbladder epithelial cell, and these lipids or their derivatives influence gallbladder epithelial cell function in myriad ways. In addition, mechanisms to extrude potentially noxious biliary constituents are present on the apical plasma membrane. By these means, the gallbladder keeps attuned to and responds to the biliary environment. In this paradigm, the gallbladder appears as an astute organ that actively communicates with and participates in controlling the harsh environment that exists beyond the confines of its apical plasma membrane.
The machinery underlying gallbladder epithelial cell function, from intracellular signaling pathways to plasma membrane transport events, is beginning to be understood at the cellular and molecular level. For example, specific transporters for cholesterol and phospholipid, for bile salts, and for specific cations and anions have been identified and characterized. Despite these advances, gaps remain in our understanding of the mechanisms of gallbladder epithelial cell function and regulation.
Some of these gaps, such as the role of aquaporins in water transport in the gallbladder and the role of nuclear hormone receptors in the transcriptional control of gallbladder function, have been pointed out in this chapter and represent areas of future research. Finally, this review has highlighted the important role that gallstone pathogenesis has played in providing the impetus for research in this field. In the era of laparoscopic cholecys-tectomy, the continued importance of studying gallbladder physiology should not be overlooked.
The gallbladder provides an ideal model system to study a variety of cellular transport systems, the features of which are shared with polarized epithelial cells from its neighbors, the liver, the small intestine, and the kidneys. In particular, the interactions that take place at the apical plasma membrane of gallbladder epithelial cells with bile are likely to have relevance for protein–mediated and physical chemical events that occur at the canalicular membrane of the hepatocyte and the apical membrane of the villous enterocyte.
The uniform nature of the gallbladder epithelium, the extremely concentrated bile encountered at this interface, and the dynamic nature of the relation between the gallbladder epithelial cell and bile are features that can be exploited in the experimental setting.
What is Bile?
Bile is a greenish-brown alkaline fluid (consisting of waste products, cholesterol, and bile salts). Bile is not a digestive enzyme, but, the bile salt functions in a similar manner, in that it emulsifies large fat droplets. Bile’s primary function in the digestive system is to breakdown fats. Bile is secreted from the gallbladder (where it is stored) then enters the small intestine in response to a hormone called cholecystokinin (which gets released when food enters the small intestine from the stomach). Once bile enters the duodenum (the first section of the small intestine) it goes to work breaking down ingested fat, as well as fat-soluble vitamins, improving the ingested solubility of digested fat, facilitating its absorption.
What Are Gallstones Made of?
Gallstones are small, pebble-like substances that develop in the gallbladder. The gallbladder is a small, pear-shaped sac located below your liver in the right upper abdomen. Gallstones form when liquid stored in the gallbladder hardens into pieces of stone-like material. The liquid—called bile—helps the body digest fats. Bile is made in the liver, then stored in the gallbladder until the body needs it. The gallbladder contracts and pushes the bile into a tube—called the common bile duct—that carries it to the small intestine, where it helps with digestion.
Bile contains water, cholesterol, fats, bile salts, proteins, and bilirubin—a waste product. Bile salts break up fat, and bilirubin gives bile and stool a yellowish-brown color. If the liquid bile contains too much cholesterol, bile salts, or bilirubin, it can harden into gallstones.
The two types of gallstones are cholesterol stones and pigment stones. Cholesterol stones are usually yellow-green and are made primarily of hardened cholesterol. They account for about 80 percent of gallstones. Pigment stones are small, dark stones made of bilirubin. Gallstones can be as small as a grain of sand or as large as a golf ball. The gallbladder can develop just one large stone, hundreds of tiny stones, or a combination of the two.
“Gallstones can be painful, and cause obstruction,” Knowlton said. “Depending on where the obstruction is, [it] causes a variety of problems: gallbladder obstruction (cholecystitis), biliary tree obstruction (jaundice) and pancreatic duct obstruction (pancreatitis).” Gallstones can block the gallbladder ducts so that bile cannot reach the small intestine as effectively, which may prevent the gallbladder from doing its job and can lead to other gallbladder diseases.
Where Is Your Gallbladder Located?
Cholecystitis is the most common type of gallbladder disease, and often what medical professionals associate with the phrase. Knowlton described it as “inflammation of the gallbladder.” It is caused by gallstones obstructing the ducts to the small intestine. In addition to upper right abdominal pain, Knowlton said, cholecystitis carries with it a variety of symptoms, “including fever, positive Murphy’s sign [pain when the abdominal area is examined], nausea and vomiting.” She said, “treatment depends on the severity of the symptoms … this can often be managed by rest and antibiotics, but for severe cases, surgery is the definitive treatment.”
Gallstones are hard nuggets of material that can form in your gallbladder. They can be made up of cholesterol or a bile salt called bilirubin and can vary in size.
Calculous cholecystitis is the most common type of cholecystitis and accounts for around 95 percent of all cases. This happens when the cystic duct specifically gets blocked by a gallstone or a type of bile called biliary sludge.
According to the NIH, after several attacks of pain, chronic cholecystitis may occur. This involves the gallbladder shrinking and losing its function.
“Those prone to gallbladder disease usually fall into the “5 F’s”: fair, fat, 40, female, and flatulent!” said Knowlton.
Choledocholithiasis is the “presence of at least one gallstone in the common bile duct,” according to Penn Medicine. It can block the flow of bile and cause the gallbladder to become inflamed or distended.
Acalculous gallbladder disease occurs without the presence of gallstones, according to the University of Maryland Medical Center. It happens when the gallbladder muscles or valve are not working correctly, and is often found in patients who are suffering from other serious disorders.
Cholangitis is inflammation in the common bile duct. According to the Medical University of South Carolina’s Digestive Disease Center, the most common cause is gallstones becoming lodged in the bile duct, though the condition can also be caused by bacterial infections, blockages caused by medical procedures, and tumors.
Gallbladder cancer is relatively rare, according to the Mayo Clinic. It can be difficult to diagnose because its symptoms are similar to other gallbladder ailments (nausea, vomiting, jaundice, fever).
Gallbladder polyps are lesions or growths in the gallbladder that are usually harmless and carry no symptoms, according to Healthline. The University of Southern California Center for Pancreatic and Biliary Diseases, however, warns that they can occasionally be a risk factor for gallbladder cancer.
Gangrene results from inadequate blood flow and can develop in the gallbladder if acute cholecystitis is left untreated. The NIH lists the following symptoms: confusion, fever, gas in tissues under the skin, feeling ill, low blood pressure and persistent pain.
Abscesses occur when the gallbladder becomes inflamed with pus. Like gangrene, it can occur as a complication of acute cholecystitis, according to The New York Times.
Signs and Symptoms of Gallbladder Problems
Most gallbladder symptoms start with pain in the upper abdominal area, either in the upper right or middle.
Specific symptoms may vary according to what type of gallbladder condition you have, although many symptoms are common among the various types of gallbladder problems.
Here are some common symptoms of gallbladder problems:
- Severe pain in the upper right or center of your abdomen
- Tenderness in the abdomen, particularly the right upper quadrant
- Abdominal pain lasting several hours
- Pain that may extend beneath the right shoulder blade or to the back
- Pain that worsens after eating a heavy meal, particularly fatty or greasy foods
- Pain that feels dull, sharp, or crampy
- Pain that increases when you breathe in deeply
- Heartburn, indigestion, and excessive gas
- Chest pain
- A feeling of fullness in the abdomen
- Fever, ranging from low-grade to severe
- Shaking with chills
- Stools of an unusual color (often lighter, like clay)
- Dark urine (often described as tea-colored)
- Some gallbladder problems, like simple gallstones that are not blocking the bile ducts, often cause no symptoms at all.
They’re most often discovered during an X-ray or CT scan that’s performed to diagnose a different condition, or even during abdominal surgery.
If you spot any symptoms of gallbladder trouble, see your doctor for a diagnosis and prompt treatment to get your digestive tract running smoothly again.
It’s essential to seek immediate treatment if you develop a severe gallstone complication that causes any of the following symptoms:
- Abdominal pain so severe you can’t sit or lie still or keep food down
- Jaundice (yellowing of the skin and eyes)
- Severe fever with chills
- Abdominal ultrasound: a noninvasive test in which a probe on the skin bounces high-frequency sound waves off structures in the belly. Ultrasound is an excellent test for gallstones and to check the gallbladder wall.
- HIDA scan (cholescintigraphy): In this nuclear medicine test, radioactive dye is injected intravenously and is secreted into the bile. Cholecystitis is likely if the scan shows bile doesn’t make it from the liver into the gallbladder.
- Endoscopic retrograde cholangiopancreatography (ERCP): Using a flexible tube inserted through the mouth, through the stomach, and into the small intestine, a doctor can see through the tube and inject dye into the bile system ducts. Tiny surgical tools can be used to treat some gallstone conditions during ERCP.
- Magnetic resonance cholangiopancreatography (MRCP): An MRI scanner provides high-resolution images of the bile ducts, pancreas, and gallbladder. MRCP images help guide further tests and treatments.
- Endoscopic ultrasound: A tiny ultrasound probe on the end of a flexible tube is inserted through the mouth to the intestines. Endoscopic ultrasound can help detect choledocholithiasis and gallstone pancreatitis.
- Abdominal X-ray: Although they may be used to look for other problems in the abdomen, X-rays generally cannot diagnose gallbladder disease. However, X-rays may be able to detect gallstones.