Gallstones are small rocks or crystals that form in the gallbladder. Gallstones vary in size and number. Some are small as sand, others are bigger than an inch. There may be one, or there may be hundreds. Low calorie, rapid weight-loss diets increase the risk.
Women are twice as likely as men to have gallstones.
Pregnancy and birth control pills predispose women to gallstones. Most people with gallstones have no symptoms at all. Silent stones do not require any treatment. The pain may be perceived between the shoulder blades or in the right shoulder. It is often accompanied by bloating, nausea, or vomiting.