Hi, Thanks for writing in to us. Nonalcoholic fatty liver disease is a term used to describe the accumulation of fat in the liver of people who drink little or no alcohol. 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. Unfortunately, elevated AST and ALT values do not discriminate between the presence of simple steatosis or the more serious NASH. As a result, referral to a liver specialist (hepatologist) may be necessary to determine the presence and severity of NASH. The hepatologist may perform other blood tests. Liver X-rays including ultrasound or CT scans may be used to confirm the presence of fat in the liver but do not help determine more important features—the amount of inflammation or scarring. The definitive method to confirm both the presence and severity of NASH is to perform a liver biopsy. In this procedure, a very small sample of liver tissue is obtained by inserting a needle through the skin into the liver. The tissue is examined under the microscope to confirm the precise nature of NAFLD and its severity. Hope this helps