What causes gallstones?

The individual cause is not known but factors that predispose to the formation of gallstones apart from age and gender are:

• Oestrogen hormones given as the contraceptive pill or for hormone replacement therapy
• High intake of cholesterol in the diet or diet rich in carbohydrates
• Drugs used to reduce blood cholesterol
• Disease affecting cholesterol metabolism (hypercholesterolaemia)
• Diabetes mellitus
• Rapid weight loss or prolonged fasting