Why Fatty Liver Disease Got a New Name in 2023

In 2023, a multi-society consensus renamed two familiar conditions: NAFLD became MASLD, and NASH became MASH. The conditions themselves didn't change — the name did, and the reason why is worth understanding. MASLD stands for metabolic dysfunction-associated steatotic liver disease. MASH stands for metabolic dysfunction-associated steatohepatitis, a more advanced form involving liver inflammation. Both now sit under a broader umbrella term, steatotic liver disease (SLD). A related category, MetALD, covers patients who have MASLD and also drink alcohol above defined thresholds. Why rename it at all? The old name, "non-alcoholic fatty liver disease," was defined by what it wasn't — not caused by alcohol — rather than by what actually drives it. The new name names the real driver: metabolic dysfunction, closely tied to insulin resistance, obesity, and related conditions. That's a more useful description both for research and for explaining the condition to patients. For patients, practically, nothing about the diagnosis or evaluation process has changed. If an older lab report or a doctor used the terms NAFLD or NASH, that refers to the same condition now called MASLD or MASH — the underlying liver findings and the reasons to manage it (weight, glucose, and cholesterol) are unchanged. That connection is really the main point: MASLD is best understood as a metabolic condition that happens to show up in the liver, which is why it's so often discussed alongside diabetes, obesity, and cholesterol rather than as a separate, unrelated diagnosis.