Causes of Gallstones
The causes of gallstones involve an imbalance in the substances that make up bile, particularly cholesterol, bile salts, and bilirubin. Gallstones form when these substances become too concentrated and crystallise inside the gallbladder.
Cholesterol Stones
The most common type, especially in Western countries
Caused when bile contains too much cholesterol, too little bile salts, or not enough fluid
High-fat diets, obesity, and lack of physical activity can contribute to this imbalance
Pigment Stones
Made from excess bilirubin, a substance produced when the body breaks down red blood cells
More common in people with:
Liver disease
Certain blood disorders like sickle cell anaemia
Infections in the biliary system
Sludge Formation
Before actual stones develop, bile may become thick and form sludge—a precursor to gallstones. This often occurs:
During rapid weight loss
In people receiving intravenous feeding
During pregnancy due to hormonal changes
Risk Factors
Gallstones are more likely in people who are:
Over 40 years old
Female – due to hormonal influences of oestrogen
Overweight or obese
Following a high-fat, low-fibre diet
Living a sedentary lifestyle
Other contributing factors include:
Family history of gallstones
Pregnancy
Use of oral contraceptives or hormone replacement therapy
Certain medical conditions like diabetes or Crohn’s disease
Ethnicity and Geography
Gallstones are more common in people of Native American, Hispanic, or South Asian descent
Western dietary habits are associated with higher prevalence compared to other regions
Causes of Gallstones
Understanding the causes of gallstones allows at-risk individuals to take preventive steps—such as maintaining a healthy weight, eating a balanced diet, and staying active.
