Gallstones are most common in women, people who are obese, older people, people with sickle cell disease, people who have lost weight rapidly, and people who are taking certain medicines. Diets high in cholesterol have also been implicated in the formation of gallstones as well. Gallstones generally do not cause problems unless they block the outlet of the gallbladder (called the cystic duct) or the bile duct itself. For more information, click on Gallstones on the right-hand side of this page.