Gallstones are an accumulation of cholesterol and other substances found in the bile that occasionally block a duct connecting the gallbladder and small intestine. A gallstone can be as tiny as a grain of sand or as large as a golf ball. Many gallstones do not cause problems; only 1-2% of those with gallstones develop disease. A person can develop a single gallstone or several.

Bile is produced by the liver and used to digest fats. When too much cholesterol builds up in the bile or a person’s gallbladder does not empty properly, crystals, or gallstones, can form. Symptoms of gallstones include pain in the stomach or just under the ribs. Often, the pain can make it difficult to breathe or get comfortable. The pain sometimes occurs after a meal, can last several hours, and can even wake a person from sleep.

When a stone blocks the duct that drains the gallbladder, other symptoms can include nausea, vomiting, and fever, in addition to pain. Some patients must have surgery to remove the gallbladder. Occasionally, gallstones can cause another condition, pancreatitis, which blocks the flow of digestive enzymes produced by the pancreas. In this case, the symptoms are similar: severe pain, loss of appetite, fever, nausea, and vomiting.

Those at risk for gallstones include females, people over 55, those who are overweight or have a high body mass index, and people who lose weight rapidly. People of Native American or Hispanic descent, along with those who get little exercise or fast periodically, are also at risk. Others at increased risk of gallstones have elevated triglycerides, a disease of the intestines, or family members with a history of gallstones.

Pregnant women and those taking estrogen or high-dose birth control pills can also be at risk for developing gallstones. Sufferers of cirrhosis or sickle cell disease and people who take cholesterol-lowering medicines might have an increased risk of gallstones. Any one experiencing severe abdominal pain should see a doctor. People who are over 60 or have a heart condition, diabetes, or an impaired immune system should seek immediate medical attention.

Ultrasounds and scans are used to diagnose gallstones. Medications are not commonly used to treat gallstones, but might be necessary for patients who cannot withstand surgery. When the gallbladder is removed, the symptoms normally do not return.

To prevent gallstones, maintain a healthy weight, eat a balanced diet and get regular exercise. Also, avoid rapid weight loss and subsequent weight gain to reduce the risk of developing gallstones.