Gallstones or cholelithiasis are hardened deposits of digestive fluid that form in the gallbladder. As a result, the bile duct becomes blocked, and bile cannot be released into the intestine, causing symptoms. Their size can vary from small, like a grain of sand, to large, like golf balls.
Gallstones
It is one of the most common diseases worldwide, with a prevalence that varies between 5% and 25% depending on geographic origin, sex, and age.
The main cause of gallstone formation is not entirely clear, although it is known that they are caused by excess cholesterol or bilirubin in the bile. It can also occur if the bile does not empty properly or frequently enough. Certain people are more prone to developing them due to significant influencing risk factors.
- Sex: more common in women.
- Pregnancy.
- Hormonal treatments with estrogens.
- Age.
- Ethnic origin: more common in Native Americans and less common in people of African descent.
- Obesity.
- Elevated cholesterol and triglyceride levels.
- Rapid weight loss.
- High-calorie diet.
- Lack of physical activity.
- Hemolysis and chronic bacterial or parasitic infections.
Symptoms
Many people with gallstones do not have any symptoms.
Gallstones are often discovered as an incidental finding when abdominal X-rays are taken.
However, if a large stone blocks a tube or duct that drains the gallbladder, colicky pain can occur in the middle to upper right part of the abdomen, known as biliary colic. The pain disappears if the stone passes into the first part of the small intestine.
Symptoms that may occur include:
- Pain in the upper right or middle part of the abdomen for at least 30 minutes. The pain may be constant or colicky. It can be sharp or dull.
- Fever.
- Yellowish discoloration of the skin and the whites of the eyes (jaundice).
Other less common symptoms may include:
- Clay-colored stools.
- Nausea and vomiting.
Prevention
Genetic factors seem to play an important role in cholelithiasis, making its prevention more difficult. However, there are some recommendations to help avoid gallstones:
- Maintain a healthy weight and avoid rapid weight loss.
- Follow a healthy and balanced diet.
- Exercise regularly.
- Avoid certain medications (those for lowering cholesterol or hormone therapy).
Number of observed variants
13.5 million variants
Number of risk loci
21 loci
Genes analyzed
Bibliography
Ferkingstad E, Oddsson A, Gretarsdottir S, et al. Genome-wide association meta-analysis yields 20 loci associated with gallstone disease. Nature Communications. 2018 Nov;9(1):5101.
Portincasa, P., Moschetta, A. & Palasciano, G. Cholesterol gallstone disease. Lancet 2006;368 (9531):230-239.