Fatty liver is the buildup of fat in the liver cells. It is a liver condition that may be benign (harmless), but sometimes may contribute to the development of more serious liver conditions, such as inflammation (hepatitis) and scarring of liver tissue (cirrhosis).

There are two major forms of fatty liver: alcoholic and nonalcoholic. When fatty liver occurs alone, it is called steatosis. When it occurs with inflammation or liver cell damage, it is called steatohepatitis. When patients have steatohepatitis but do not drink alcohol, it is called nonalcoholic steatohepatitis (NASH).

In the United States and other Western countries, the main causes of fatty liver include alcohol abuse, obesity and diabetes, a disorder in the body’s ability to use blood sugar. Other causes may include pregnancy and medications such as corticosteroids.

Fatty liver often produces no symptoms. When symptoms are present, they may include fatigue, malaise or abdominal tenderness. If fatty liver develops into a more serious condition, symptoms may include jaundice, weight loss and swelling (edema) in the legs and feet.

Fatty liver is frequently identified while testing for other conditions. A physical examination, medical history and blood tests such as a liver function test may provide some indications of the condition. Fatty liver can be confirmed by removing a small piece of tissue for a liver biopsy.  

Treatment of fatty liver consists of treating its underlying cause. For example, abstinence from alcohol can stop or even reverse fatty liver. Obese people who lose weight and exercise regularly may also reverse this condition. However, any cell death or scarring that results from untreated fatty liver disease is permanent and can impair liver function if severe (e.g., cirrhosis). Other fatty liver treatments that are being studied include vitamins E and C, milk thistle and omega-3 fatty acids.

Some cases of fatty liver cannot be prevented. Others may be prevented by limiting alcohol, maintaining a healthy weight and maintaining normal levels of cholesterol and triglycerides.