Fatty Liver: Fatty liver disease (NASH, NAFLD, nonalcoholic fatty liver disease and nonalcoholic related steatohepatitis) is a disease where by there is an increased accumulation of fat in the liver. This fat accumulation can lead to cirrhosis and possibly liver cancer. Fatty liver disease is caused by a diet high in fat and calories, association with other diseases and conditions, and certain medications. Treatment for fatty liver disease depends on the cause of fat accumulation in the liver.