The more severe form of nonalcoholic fatty liver disease (NAFLD) is called nonalcoholic steatohepatitis (NASH). NASH causes the liver to swell and may lead to liver scarring. NASH tends to develop in people who are overweight or obese, or have diabetes, high cholesterol or high triglycerides. However, some people have NASH even if they do not have any risk factors. Most people with NASH are between 40 and 60 years old. NASH is more common in women than in men. NASH often has no symptoms, and people can have NASH for years before symptoms occur. NASH is one of the leading causes of cirrhosis in adults in the United States. Up to 25 percent of adults with NASH may develop cirrhosis, according to the American Liver Foundation.