Nonalcoholic fatty liver disease is common and, for most people, causes no signs and symptoms and no complications. But in some people with nonalcoholic fatty liver disease, the fat that accumulates can cause inflammation and scarring in the liver. This more serious form of nonalcoholic fatty liver disease is sometimes called nonalcoholic steatohepatitis. At its most severe, nonalcoholic fatty liver disease can progress to liver failure.