Nonalcoholic fatty liver (NAFL, or fatty liver) is a buildup of fat in the liver in people who drink little or no alcohol. Fatty liver is the most common type of nonalcoholic fatty liver disease (NAFLD).

Having a fatty liver isn't normal, but it may not cause liver damage. But some people may develop a more serious type of NAFLD called nonalcoholic steatohepatitis (NASH). This causes liver inflammation, which can lead to cirrhosis and liver failure.

Experts don't really know what causes fat buildup in the liver, but being obese seems to increase the risk. Most people who have a fatty liver also have one or more of a group of health problems called metabolic syndrome. This includes obesity, high cholesterol, high blood pressure, and insulin resistance or diabetes.

Most people who have a fatty liver have no symptoms. It's usually diagnosed with blood tests and imaging tests, such as a CT scan, an ultrasound, or an MRI.

Treatment focuses on managing related conditions like diabetes and making lifestyle changes, including losing weight if needed, eating a healthy diet, and being more active. Weight-loss options may include medicines or surgery.