The gallbladder is a small, pear-shaped organ that stores bile, a greenish-yellow digestive fluid.
In humans, it is found on the underside of the right side of the liver, as can be seen in Innerbody.
It can hold about 1 1/2 ounces of bile at a time. Bile is made up of bile salts, bilirubin, cholesterol, fatty acids, water, phospholipids and other chemicals.
What is the Gallbladder? How Does it Work?
The stem or the neck of the bladder connects with the cystic duct, which is a tube that travels to the liver’s hepatic duct. When these tubes meet they form the common bile duct.
When a person eats, bile flows from the liver, through the hepatic duct, and into the common bile duct.
It then empties into the first part of a person’s small intestine, which is called the duodenum.
When a person isn’t eating, the bile continues to flow out of the liver through the common bile duct.
However, it’s kept out of the duodenum by a ringlike muscle that’s called the sphincter of Oddi. When the bile isn’t needed, this sphincter closes up and keeps the bile out of the duodenum.
Because the bile is still being secreted by the liver, it is forced back into the gallbladder for storage.
When the bile in the gallbladder is needed again, a hormone called cholecystokinin causes the gallbladder to contract.
Cholecystokinin is made in the upper part of the small intestine. Watch this video from Sam Webster to see how the gallbladder works.
What are the Disorders of the Gallbladder?
Normally, the gallbladder does its work painlessly, but a gallbladder that is not working the right way can cause the person to feel discomfort in the upper right part of their abdomen.
This condition is common, as is a condition called cholecystitis, which is an inflammation of the gallbladder.
This inflammation is caused often but not exclusively by gallstones. Some people have inflammation without gallstones, a condition called acalculous cholecystitis.
Acalculous cholecystitis can occur because of prolonged fasting, another severe illness or for what looks like no reason at all.
About 10 percent of Americans have gallstones, according to U.S. News and World Report Health.
Gallstones can be asymptomatic, and even if they are discovered physicians don’t treat them unless they start to cause problems.
Types of Gallstones
There are three types of gallstones. They are:
- Stones made from cholesterol
- Stones made from pigment
- Mixed gallstones
Some medical experts add a fourth category of gallstones made entirely of minerals such as calcium salts, silicon or aluminum.
Stones that are made purely of cholesterol or pigment are rare in the United States.
Pigmented stones are common in Asia and places where people are more at risk for parasitic infections of the liver and gallbladder.
In the United States, pigmented stones are caused by the destruction of red blood cells or cirrhosis of the liver due to alcoholism.
The medical term for gallstones is cholelithiasis. The stone comes in many sizes, from the size of a grain of sand to a ball that takes up much of the bladder itself.
There can be one or hundreds of stones in a person’s gallbladder.
Gallstones form when the materials in the bile to harden, says Mayo Clinic. This might be because there is too much cholesterol in the system or too much bilirubin.
Bilirubin is a pigment that’s a byproduct of the liver breaking down hemoglobin, says Wikipedia.
The person may not be producing enough bile salts, which are actually acids that help the body digest fats and fat-soluble vitamins when they enter the small intestine. In other cases, the gallbladder is not emptying as efficiently as it should.
Most gallstones are mixed. Women are four times more likely than men to have gallstones.
A stone that becomes caught in the neck of the gallbladder or in a duct can inflame it and cause great pain.
The person may feel a sharp pain in their upper right abdomen, between their shoulder blades or even in their right shoulder.
Other symptoms are nausea and vomiting, bloating or belching. Some people develop a fever and jaundice, which is a yellowing of the skin and eyes as the ducts are blocked.
Though people have been born with gallstones, the risk of contracting gallstones increases with age, and the average patient is about 50.
People are also at risk if gallstones run in their family. Some ethnic groups are more susceptible to gallstones.
They are more likely to occur in people who are overweight or diabetic. Women who have high levels of estrogen are also at greater risk as are people who lose a lot of weight quickly.
People who eat a diet that’s high in fat and low in dietary fiber are more likely to get gallstones, as are people who have had certain kinds of bariatric surgery.
Specifically, these are surgeries that reduce the stomach. Interestingly, cholesterol-lowering drugs also put a person at higher risk for gallstones because they increase the amount of cholesterol in the bile.
There are several ways to treat gallstones. In a cholecystectomy, the gallbladder is simply removed.
A person can live without their gallbladder, but the liver will continue to secrete bile whether the person is eating or not.
Some doctors break the stones up through shockwaves. This is called extracorporeal shockwave lithotripsy.
During this treatment, the patient lies in a bath, which conducts the shockwaves. The doctor finds the stones via ultrasound, and their position is fed into a computer.
This treatment is followed by months of the patient taking a drug called ursodiol, which is a bile salt that fully dissolves what’s left of the stones.
If the patient has tiny stones, they may only need to take the medication. Another bile acid used to treat gallstones is chenodeoxycholic acid.
What is Gallbladder Cancer?
Gallbladder cancer occurs when cells in the gallbladder become malignant and grow out of control.
It is rare cancer, according to the Centers for Disease Control and Prevention, but having gallstones raises the risk of getting it.
Since there are no symptoms in the early stages, most gallbladder cancers are found when the patient goes to their doctor to be treated for gallstones.