Hepatic Steatosis and Fatty Liver Are the Same Condition
Yes, hepatic steatosis and fatty liver are identical terms referring to the same pathological condition—the abnormal accumulation of triglycerides in hepatocytes exceeding 5% of liver cells. 1, 2
Terminology and Definition
The terms are used interchangeably in clinical practice and medical literature:
- Hepatic steatosis is the formal medical/histological term describing fat accumulation within liver cells 1, 3
- Fatty liver or fatty liver disease is the more colloquial clinical term for the same condition 4, 5
- Both require ≥5% fat accumulation in hepatocytes by histology or >5.6% proton density fat fraction by magnetic resonance spectroscopy for diagnosis 1, 2
The Disease Spectrum Context
While the terms are synonymous, it's critical to understand that hepatic steatosis/fatty liver represents only the initial stage of a broader disease spectrum 1, 6:
- Simple steatosis (NAFL) occurs in 70-75% of cases—fat accumulation without inflammation or hepatocyte injury, carrying minimal risk of progression to cirrhosis 2, 6
- Steatohepatitis (NASH/MASH) occurs in 25-30% of cases—fat accumulation plus inflammation with hepatocyte ballooning, representing a critical pathophysiologic transition with higher risk of progression to cirrhosis, liver failure, and hepatocellular carcinoma 2, 6
Common Clinical Pitfall
The majority (60-80%) of patients with hepatic steatosis remain completely asymptomatic because simple fat accumulation occurs without cellular injury or inflammation, and the liver capsule lacks pain receptors for stretch or fat accumulation alone 7, 6. This silent presentation makes early detection challenging and underscores the importance of screening high-risk populations (obesity, diabetes, metabolic syndrome) even when liver biochemistries appear normal 6.
Etiologic Diversity
Hepatic steatosis/fatty liver can result from multiple pathogenic mechanisms 4, 8:
- Metabolic dysfunction (obesity, insulin resistance, diabetes)—most common cause 1, 2
- Alcohol consumption above threshold limits (≥30 g/day for men, ≥20 g/day for women) 1
- Medications with steatogenic properties 2
- Viral hepatitis, genetic disorders, toxins 4, 8
The diagnosis requires exclusion of secondary causes and significant alcohol consumption to establish metabolic dysfunction-associated steatotic liver disease (MASLD), formerly called NAFLD 1, 2.