The bile is the liquid inside the gallbladder. It is produced by the liver and then kept inside the gallbladder until fat digestion is needed. It will then be pushed by the gallbladder into the common bile duct and then it will get inside the small intestine where it will perform its digestive function.

The bile is made out of water, bile salts, cholesterol, fats, proteins, and bilirubin. All these components give bile its yellowish color and break up the fats. The reason why gallstones form out of bile is because sometimes this bile composition can change containing a lot of cholesterol or a lot of bile salts and bilirubin.

Cholesterol stones have a yellow-greenish color and are made of cholesterol most of all. 80% of the gallstones are represented by cholesterol stones.

Another type of gallstones is that made out of pigment (bilirubin) and is small and dark.

The size of the gallstones is varied. Some stones are tiny but others can occupy the whole place in the gallbladder. Sometimes inside the gallbladder doctors find one stone and in other patients they might find 2 to 10 stones of different sizes and shapes.

The biliary system is made out of the gallbladder and the ducts. This system is carrying the bile from the liver towards the small intestine to help in the digestion process.

Gallstones can interfere with the bile's normal flow and can block it if they get stuck in any of the small ducts: the hepatic ducts, the cystic duct and the common bile duct. If the bile gets locked inside one of these ducts complications like pancreatitis or gallbladder inflammation can occur. Signs of such a problem are: jaundice, fever and intense pain that lasts a long time.

Gallstones form due to an increased quantity of cholesterol inside the bile, due to biliary tract infections and other assumptions like: hereditary blood disorders and cirrhosis.

Other factors that lead to gallstones formation are: obesity, ethnicity, age, gender, diabetes and rapid weight loss.

Obesity is considered a factor of risk because it reduces the amount of bile salts in bile and so cholesterol will be in an increased amount inside that bile.

Native Americans have a genetic predisposition for developing gallstones. They seem to secrete more cholesterol inside the bile than needed. Most of all those aged over 60 are suspected to be at risk of developing gallstones more frequent than others aged less then 60.

Women are exposed to this disease more than men. They might develop gallstones between 20 and 60 years of age. It seems that among the Pima Indians of Arizona 70% of the women aged under 30 have gallstones already. Mexican American men and women have a high risk of developing this affection too.

Those who have diabetes are considered to be exposed to gallstones because they have high levels of triglycerides which increase the risk of gallstones.

Is someone looses weight in a short while the fat will be metabolized by the body during this loss of weight and will determine the liver to secrete more cholesterol in the bile, resulting the gallstone's formation.

Also, pregnant women and those who follow hormone therapy based on estrogens can develop gallstones. Estrogen has been proven to increase the level of cholesterol inside the bile and decrease the gallbladder's movements.

Gallstones can give symptoms that look like attacks because they install suddenly.

Some of the classic symptoms are: nausea and vomiting, pain in the right upper abdomen that gets worse as time passes and pain in the right shoulder and the area between the shoulder blades. Bloating, belching, gas, jaundice, fever and indigestion are also present in such an attack.

Sometimes the gallstones give no symptoms and are considered to be silent stones. They generally do not interfere with the pancreas or gallbladder and to not require treatment.

Diagnosing gallstones is usually made by accident, especially the silent ones while performing some tests for other problems. If the doctor suspects that you feel sick because of gallstones he will ran an ultrasound test to see if gallstones are present. These ultrasounds are not harmful and are used even when showing the baby to the pregnant mother.

Other tests can also be performed like the CT which will show the complications too. A magnetic resonance cholangiogram can be used when suspecting that the bile ducts have been blocked by the gallstone. For showing a malfunction in the contraction of the gallbladder the cholescintigraphy will be used. This means that a radioactive material will be injected in the body and it will stimulate the gallbladder to contract showing any abnormalities in this process. Sometimes even blood tests will be requested to see signs of possible infection, obstruction or pancreatitis.

Doctors know that the symptoms of gallstones are similar to those of appendicitis, pancreatitis, hepatitis, heart attack and ulcers and will perform tests to eliminate these diseases before diagnosing gallstones.