Cholesterol gallstones develop when bile contains too much cholesterol and not enough bile salts. Besides a high concentration of cholesterol, two other factors are important in<unk> ng gallstones. The first is how often and how well the gallbladder contracts; incomplete and infrequent emptying of the gallbladder may<unk>  the bile to become overconcentrated and contribute to gallstone formation. This can be<unk> d by high resistance to the flow of bile out of the gallbladder due to the complicated internal geometry of the cystic duct. The second factor is the presence of proteins in the liver and bile that either promote or inhibit cholesterol crystallization into gallstones. In addition, increased levels of the hormone estrogen, as a result of pregnancy or hormone therapy, or the use of combined (estrogen-containing) forms of hormonal contraception, may increase cholesterol levels in bile and also decrease gallbladder motility, resulting in gallstone formation. Composition From left to right: cholesterol stone, mixed stone, pigment stone. The composition of gallstones is affected by age, diet and ethnicity. On the basis of their composition, gallstones can be divided into the following types: cholesterol stones, pigment stones, and mixed stones. An ideal classification system is yet to be defined. Cholesterol stones Cholesterol stones vary from light yellow to dark green or brown or chalk white and are oval, usually solitary, between 2 and 3 cm long, each often having a tiny, dark, central spot. To be classified as such, they must be at least 80% cholesterol by weight (or 70%, according to the Japanese–classification system). Between 35% and 90% of stones are cholesterol stones. Pigment stones Bilirubin ("pigment", "black pigment") stones are small, dark (often appearing black), and usually numerous. They are composed primarily of bilirubin (insoluble bilirubin pigment polymer) and calcium (calcium phosphate) salts that are found in bile. They contain less than 20% of cholesterol (or 30%, according to the Japanese-classification system). Between 2% and 30% of stones are bilirubin stones. Mixed stones Mixed (brown pigment stones) typically contain 20–80% cholesterol (or 30–70%, according to the Japanese- classification system). Other common constituents are calcium carbonate, palmitate phosphate, bilirubin and other bile pigments (calcium bilirubinate, calcium palmitate and calcium stearate). Because of their calcium content, they are often radiographically visible. They typically arise secondary to infection of the biliary tract which results in the release of β-glucuronidase (by injured hepatocytes and bacteria) which hydrolyzes bilirubin glucuronides and increases the amount of unconjugated bilirubin in bile. Between 4% and 20% of stones are mixed. Gallstones can vary in size and shape from as small as a grain of sand to as large as a golf ball. The gallbladder may contain a single large stone or many smaller ones. Pseudoliths, sometimes referred to as sludge, are thick secretions that may be present within the gallbladder, either alone or in conjunction with fully formed gallstones. File:Gallstones.Gallbladder opened to show small cholesterol gallstones File:Gallstone µCT.X-ray microtomograph of a gallstone File:Gallstones.The large, yellow stone is largely cholesterol, while the green-to-brown stones are mostly composed of bile pigments File:Gallenstein FRONT.CT images of gallstones File:Big Gallstone.Large gallstone File:Human gallstones 2015 G1.Numerous small gallstones made up largely of cholesterol
medical cause of Pancreatitis
symptom of Gallbladder cancer
symptom of Pancreatic cancer
symptom of Primary biliary cholangitis
symptom of Liver cancer
symptoms of Primary biliary cholangitis
complications of Gallstone
medical cause of Ascites