80 % of gall stones contain
**Core Concept**
Cholesterol stones are a common type of gallstone, and understanding their composition is crucial for diagnosing and managing gallstone disease. Gallstones are formed when bile components, such as cholesterol, bilirubin, or calcium salts, precipitate out of solution in the gallbladder.
**Why the Correct Answer is Right**
Cholesterol stones are the most common type of gallstone, accounting for approximately 80% of cases. They form when the concentration of cholesterol in bile exceeds its solubility, leading to the precipitation of cholesterol crystals. This can occur due to an imbalance in the bile salt:cholesterol ratio, which is influenced by factors such as diet, obesity, and genetic predisposition.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because cholesterol stones are not the only type of gallstone, but they are the most common.
**Option B:** Incorrect because pigment stones are more common in patients with bile duct obstruction or hemolytic diseases.
**Option C:** Incorrect because calcium stones are less common and typically form in the setting of hypercalcemia or certain genetic disorders.
**Clinical Pearl / High-Yield Fact**
It's essential to note that cholesterol stones are often asymptomatic and may not cause symptoms until they become large enough to obstruct the bile duct or cause inflammation of the gallbladder.
**Correct Answer: C. Cholesterol stones. Cholesterol stones are the most common type of gallstone.**