Causes and Risk Factors of Liver Cysts

Liver cysts, also called hepatic cysts, are small, fluid-filled tissue growths on the liver. They're found in about 5% to 10% of people and have a variety of causes. Several factors are involved in the development of liver cysts, including a defect that's present at birth (congenital), certain genetic diseases, or parasitic infections.

This article provides an overview of the potential causes of liver cysts.

Common Causes

There are several types of liver cysts. Here are the most common causes of each type.

• Congenital (form before birth): Experts think that most liver cysts that are not cancerous or harmful (simple liver cysts) develop in the womb. They are the most common type of liver cyst and likely form due to an abnormality in the tubes attached to the liver that help with the body's digestive process (bile ducts). These cysts are much more common after age 40 and are found in females more than males. Research has suggested this could be because the hormone estrogen encourages cyst growth. Scientists are still learning how hormonal birth control, hormone replacement therapy, and pregnancy may play a role in liver cyst development.
• Parasitic infection: The Echinococcus tapeworm, found in dogs and some farm animals, can cause liver cysts. It happens when people get infected by Echinococcus through exposure to the parasite, usually from food (e.g., vegetables) or water that was contaminated by an infected animal’s feces. This cause of liver cysts is not as common in the United States as it is in other parts of the world.
• Disease: People who have certain genetic disorders—such as polycystic liver disease (PLD) and polycystic kidney disease (PKD)—develop multiple cysts on their liver that can increase in size. Liver cysts from these inherited disorders can cause painful symptoms and other potentially dangerous complications. They require specific treatment from a specialist.

It has not been documented as frequently as other causes, but it's also possible for liver cysts to be caused by trauma to the liver—for example, after an extreme accident or injury.

Genetics

For some people, the development of liver cysts can be passed down from their parents (inherited).

Specifically, people with polycystic liver disease (PLD) and polycystic kidney disease (PKD) have abnormal changes in genes (mutations) that prompt liver cysts to form. Researchers believe PLD and PKD likely share some of the same genetic mutations. Some of the most common ones linked to the diseases are the PKD1, PKD2, PKD3, PRKCSH, LRP5, and SEC63 genes.

These conditions are usually inherited, but the gene mutation can also be new (spontaneous) in some cases. This means the diseases (and the liver cysts) could show up in people who do not have a history of the condition in their family.

If either disorder runs in your family, experts recommend looking into genetic counseling.

Lifestyle Risk Factors

Some causes of liver cysts can't be changed, like your genetics, age, or a congenital condition that you were born with.

Research has not specifically linked lifestyle factors like diet or exercise to developing liver cysts. That said, there are some general lifestyle choices that are thought to promote good health overall, including:

• Avoid taking unnecessary medications
• Eat a well-balanced diet
• Get regular exercise
• Maintain a weight that's healthy for your body type and overall health
• Quit smoking
• Drink alcohol responsibly
• Practice proper hygiene (especially when traveling or when at farms or around unknown animals)

Summary

Liver cysts are small, abnormal, fluid-filled filled growths that form on the liver. A person can be born with liver cysts or they can develop later in life. Causes of liver cysts include a parasitic infection or genetic disease. Sometimes, the cause of liver cysts is unknown.

Liver cysts are common, being found in up to 10% of the population. Most liver cysts are harmless, but those caused by an underlying condition may need specific treatment. Your healthcare provider can advise you about treatment if you have liver cysts.

A Word From Verywell

Finding out you have a cyst on your liver can feel scary. Remember that the average liver cyst is considered harmless and typically doe not cause symptoms on its own. However, you might have symptoms if you have been diagnosed with a health condition or a parasitic infection that has caused the cysts. Talk to your provider about your concerns. They can help you plan your treatment accordingly.