Steatosis is a medical condition characterized by the build-up of excess fat in the liver cells. While steatosis is the most commonly used term to describe this condition, there are several other synonyms that are used to refer to this health problem. Some of the other terms include fatty liver disease, hepatic steatosis, liver steatosis, non-alcoholic fatty liver disease (NAFLD), and non-alcoholic steatohepatitis (NASH). These terms are typically used interchangeably, and all refer to the same condition. Regardless of the term used, treatment for steatosis generally involves making lifestyle changes, such as adopting a healthier diet, losing weight, and increasing physical activity.