Gallstones are extremely common, reports the Cleveland Clinic. Gallstones develop from a thick liquid substance called bile. The liver produces bile and stores it in a small organ behind the liver called the gallbladder. Bile is a thick substance made of water, proteins, cholesterol, bile salts and bilirubin that helps to digest fat, according to the National Digestive Disease Information Council. Imbalances in cholesterol or bilirubin lead to the formation of gallstones. Bile becomes solid, forming small rock-like structures in the gallbladder. Most gallstones cause no problems at all. However, those that leave the gallbladder or grow large enough may cause symptoms.
Poor Emptying
Periodically, the gallbladder empties into the small intestines. Conditions causing the gallbladder not to empty appropriately allow bile to sit too long. This promotes the formation of stones. This frequently occurs in pregnancy, reports Medline Plus. Hormones released during pregnancy slow digestion, making it hard for the gallbladder to empty.
Increased Formation
Some conditions induce the formation of bilirubin. This sets up conditions that increases the risk of gallstone formation. Hemolytic anemia and sickle cell anemia represent two examples of conditions that increase the production of bilirubin, according to Medline Plus. Autoimmune destruction of red blood cells, characterizes the rare condition hemolytic anemia. Increased red cell destruction occurs in sickle cell anemia, as well. Products of red blood cells in high concentrations form gallstones, according to research conducted by Trotman and colleagues in "The Journal of Clinical Investigation."
Liver Disease
When the liver becomes scarred, like in liver cirrhosis, the liver makes abnormal bilirubin. Imbalances in cholesterol and bilirubin seen in conditions associated with liver disease, also promote the formation of gallstones.
Weight
One of the major risk factors for gallstones is weight. It is thought that overweight patients have reduced amounts of bile salts. This leads to the formation of stones, according to the National Digestive Diseases Information Clearinghouse.
Fad diets encouraging quick weight loss often put patients at risk for forming gallstones. Losing weight too fast also promotes conditions for the formation of gallstones. During fasting, the liver releases too much cholesterol leading to gallstones, reports the National Digestive Information Clearinghouse.
Vein Nutrition
Nutrition given through a vein is sometimes necessary when patients can not eat by mouth. These patients are typically hospitalized and very sick. This type of nutrition induces the formation of stones in the gallbladder, according to Medline Plus.
Drugs
Some drugs induce gallstone formation. The most commonly known include those drugs that lower cholesterol. Although patients experience lowered amounts of cholesterol in the blood, an increase in cholesterol occurs in bile. This leads to an increased risk of stone formation, according to National Digestive Diseases Information Clearinghouse.
Age
The Merck Manual reports, more than 20 percent of persons older than 60 years old have gallstones. As a person ages, the liver releases more cholesterol into the bile. This causes an imbalance. Older age, therefore, presents as a risk factor for the formation of gallstones, according to National Digestive Diseases Information Clearinghouse.
