Risk factors
Gallstone risk increases for females (especially before menopause) and for people near or above 40 years; the condition is more prevalent among both North and South Americans and people of European descent than among other ethnicities. A lack of melatonin could significantly contribute to gallbladder stones, as melatonin inhibits cholesterol secretion from the gallbladder, enhances the conversion of cholesterol to bile, and is an antioxidant, which is able to reduce oxidative stress to the gallbladder. Gilbert syndrome has been linked to an increased risk of gallstones. Researchers believe that gallstones may be caused by a combination of factors, including inherited body chemistry, body weight, gallbladder motility (movement), and low-calorie diet. The absence of such risk factors does not, however, preclude the formation of gallstones. Nutritional factors that may increase risk of gallstones include constipation; eating fewer meals per day; low intake of the nutrients folate, magnesium, calcium, and vitamin C; low fluid consumption; and, at least for men, a high intake of carbohydrate, a high glycemic load, and high glycemic index diet. Wine and whole-grained bread may decrease the risk of gallstones.Rapid weight loss increases risk of gallstones. The weight loss drug orlistat is known to increase the risk of gallstones.Cholecystokinin deficiency caused by celiac disease increases risk of gallstone formation, especially when diagnosis of celiac disease is delayed.Pigment gallstones are most commonly seen in the developing world. Risk factors for pigment stones include hemolytic anemias (such as from sickle-cell disease and hereditary spherocytosis), cirrhosis, and biliary tract infections.
Gallstones within the ampulla of Vater can obstruct the exocrine system of the pancreas and can result in pancreatitis. Signs and symptoms
Gallstones, regardless of size or number, are often asymptomatic. These "silent stones" do not require treatment and can remain asymptomatic even years after they form.A characteristic symptom of a gallstone attack is the presence of colic-like pain in the upper-right side of the abdomen, often accompanied by nausea and vomiting. Pain from symptomatic gallstones may range from mild to severe and can steadily increase over a period lasting from 30 minutes to several hours. Other symptoms may include fever, as well as referred pain between the shoulder blades or below the right shoulder. If one or more gallstones block the bile ducts and cause bilirubin to leak into the bloodstream and surrounding tissue, jaundice and itching may also occur. In this case, liver enzyme levels are likely to be raised.Often, gallbladder attacks occur after eating a heavy meal. Attacks are most common in the evening or at night. Other complications
In rare cases, gallstones that cause severe inflammation can erode through the gallbladder into adherent bowel, potentially causing an obstruction termed gallstone ileus.Other complications can include ascending cholangitis, which occurs when a bacterial infection causes purulent inflammation in the biliary tree and liver, and acute pancreatitis caused by blockage of the bile ducts that prevents active enzymes from being secreted into the bowel, instead damaging the pancreas. Rarely, gallbladder cancer may occur as a complication.