Gallstones are caused primarily by an imbalance in the chemical composition of bile inside the gallbladder. This imbalance often involves:
- Excess cholesterol in bile: When the liver excretes more cholesterol than the bile can dissolve, the excess cholesterol crystallizes and forms stones. About 80% of gallstones are made of cholesterol
- Excess bilirubin: Bilirubin is a chemical produced when the body breaks down red blood cells. Certain conditions like liver cirrhosis, biliary tract infections, and some blood disorders cause the liver to produce too much bilirubin, which can contribute to gallstone formation. About 20% of gallstones are made of bilirubin
- Gallbladder motility issues: If the gallbladder does not empty completely or often enough, bile becomes concentrated, increasing the risk of stone formation
Additional factors that increase the risk of developing gallstones include:
- Being female, especially during pregnancy or when taking estrogen-containing medications
- Age over 40
- Obesity or rapid weight loss
- Certain ethnic backgrounds (e.g., Native American, Hispanic of Mexican origin)
- Family history of gallstones
- Diabetes and certain blood disorders like sickle cell anemia
- Eating a high-fat, high-cholesterol, or low-fiber diet
- Conditions affecting bile flow, such as cirrhosis or Crohn’s disease
In summary, gallstones form when bile contains too much cholesterol or bilirubin or when the gallbladder does not empty properly, leading to the crystallization and growth of stones over time
