Gallstones

Gallstones (choleliths) are crystalline bodies formed within the body by accretion or concretion of normal or abnormal bile components.

Gallstones can occur anywhere within the biliary tree, including the gallbladder and the common bile duct. Obstruction of the common bile duct is choledocholithiasis; obstruction of the biliary tree can cause jaundice; obstruction of the outlet of the pancreatic exocrine system can cause pancreatitis. Cholelithiasis is the presence of stones in the gallbladder or bile ducts: chole- means "bile", lithia means "stone", and -sis means "process".

Researchers believe that gallstones may be caused by a combination of factors, including inherited body chemistry, body weight, gallbladder motility (movement), and perhaps diet. Additionally, people with erythropoietic protoporphyria (EPP) are at increased risk to develop gallstones.

Cholesterol gallstones develop when bile contains too much cholesterol and not enough bile salts. Besides a high concentration of cholesterol, two other factors seem to be important in causing gallstones. The first is how often and how well the gallbladder contracts; incomplete and infrequent emptying of the gallbladder may cause the bile to become overconcentrated and contribute to gallstone formation. The second factor is the presence of proteins in the liver and bile that either promote or inhibit cholesterol crystallization into gallstones.

In addition, increased levels of the hormone estrogen as a result of pregnancy, hormone therapy, or the use of combined (estrogen-containing) forms of hormonal contraception, may increase cholesterol levels in bile and also decrease gallbladder movement, resulting in gallstone formation.

No clear relationship has been proven between diet and gallstone formation. However, low-fibre, high-cholesterol diets, and diets high in starchy foods have been suggested as contributing to gallstone formation. Other nutritional factors that may increase risk of gallstones include rapid weight loss, constipation, eating fewer meals per day, eating less fish, and low intakes of the nutrients folate, magnesium, calcium, and vitamin C. On the other hand, wine and whole grain bread may decrease the risk of gallstones.
The common mnemonic for gallstone risk factors refer to the "four F's": fat (i.e., overweight), forty (an age near or above 40), female, and fertile (pre-menopausal);[4] a fifth F, fair is sometimes added to indicate that the condition is more prevalent in Caucasians. The absence of these risk factors does not, however, preclude the formation of gallstones.

Interestingly, a lack of melatonin could significantly contribute to gallbladder stones, as melatonin both inhibits cholesterol secretion from the gallbladder, enhances the conversion of cholesterol to bile, and is an antioxidant, capable of reducing oxidative stress to the gallbladder.

Symptoms

Gallstones usually remain asymptomatic initially. They start developing symptoms once the stones reach a certain size (>8 mm). A main symptom of gallstones is commonly referred to as a gallstone "attack", also known as biliary colic, in which a person will experience intense pain in the upper abdominal region that steadily increases for approximately thirty minutes to several hours. A patient may also encounter pain in the back, ordinarily between the shoulder blades, or pain under the right shoulder. In some cases, the pain develops in the lower region of the abdomen, nearer to the pelvis, but this is less common.[citation needed] Nausea and vomiting may occur. Patients characteristically exhibit a positive Murphy's sign: the patient is instructed to breathe in while the gall bladder is deeply palpated. If the gallbladder is inflamed, the patient will abruptly stop inhaling due to the pain, a positive Murphy's sign.

These attacks are sharp and intensely painful, similar to that of a kidney stone attack. Often, attacks occur after a particularly fatty meal and almost always happen at night. Other symptoms include abdominal bloating, intolerance of fatty foods, belching, gas, and indigestion. If the above symptoms coincide with chills, lowgrade fever, yellowing of the skin or eyes, and/or clay-colored stool, a doctor should be consulted immediately.

Some people who have gallstones are asymptomatic and do not feel any pain or discomfort. These gallstones are called "silent stones" and do not affect the gallbladder or other internal organs. They do not need treatment.