Nonalcoholic fatty liver disease (NAFLD) is the accumulation of fat in the liver. It is a benign condition and rarely causes problems. Nonalcoholic steatohepatitis (NASH) is a subgroup of NAFLD that is marked by increased inflammation in the liver. The possible end results of NASH resembles the damage found in alcoholic liver disease but the patients often drink little or no alcohol.
The exact cause for the buildup of fat and the associated damage to the liver are not known.
NAFLD is frequently found in association with obesity, insulin resistance, diabetes, high cholesterol and triglycerides. Although these conditions are commonly diagnosed with NAFLD, some patients have none of these risk factors.
NAFLD has no symptoms. NASH has no symptoms in the early stages. As the inflammation worsens, some patients develop fatigue, weight loss, and weakness. As the disease progresses, the inflammation causes damage, where resulting fibrous scar tissue (fibrosis) replaces the healthy liver tissue. Not every patient with NASH develops the most serious symptom, cirrhosis. Cirrhosis occurs when the fibrosis worsens, scarring the liver so seriously that it becomes hard and unable to function normally.
Blood panels, x rays, or types of imaging can point to NASH, but a liver biopsy is needed for a definitive diagnosis. If the resulting biopsy shows no inflammation, the diagnosis is NAFLD. The tissue must show inflammation and damage to be named NASH.
There are no specific treatments for NASH. Patients are advised to lose weight or maintain a healthy weight. In those patients who are not overweight, follow a healthy diet, get regular exercise, avoid unnecessary medications and alcohol.