MASLD is the abbreviation for Metabolic Dysfunction-Associated Steatotic Liver Disease, formerly referred to as metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD)”.MASLD is an umbrella term describing a group of liver disorders characterized by excessive fat accumulation in hepatocytes in the absence of significant alcohol consumption as the primary cause.

Steatotic Liver Disease (SLD) is the overarching category that includes MASLD as well as MASH (Metabolic Dysfunction-Associated Steatohepatitis), the progressive inflammatory form of the disease characterized by hepatocellular injury and fibrosis. In addition, the SLD nomenclature includes MetALD (Metabolic Dysfunction-Associated Alcohol-Related Liver Disease), which applies to individuals with metabolic risk factors and increased alcohol consumption. Other categories within the SLD classification are Alcohol-Associated Steatohepatitis (ASH), Drug-Induced Liver Injury (DILI) presenting with steatotic features, and Cryptogenic SLD, where no identifiable cause can be established.

Steatotic liver disease is closely associated with obesity, insulin resistance, type 2 diabetes mellitus, dyslipidemia, and other components of the metabolic syndrome. It has become one of the most common chronic liver diseases worldwide and represents a growing public health burden due to its potential progression to advanced fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related mortality.