Fatty liver disease is a spectrum, ranging from a fatty liver to cirrhosis and cancer. The disease is reversible in the earlier stages and irreversible by the later stages, meaning a diagnosis of fatty liver disease can be fluid.
Image By Signimu - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=82918485
Healthy liver: a liver that is fully functioning without any buildup of fat or inflammation
Non-alcoholic fatty liver disease (NAFLD): excess fat accumulation (steatosis) leads to the first stress of the liver; it is possible to revert back to a healthy liver at this stage
Non-alcoholic steatohepatitis (NASH): excess fat accumulation (steatosis) in the presence of inflammation, further stressing the liver; it is possible to revert back to a fatty liver or healthy liver at this stage
NASH with fibrosis: fat accumulation and continued inflammation causes liver tissue to turn into scar tissue (fibrosis), even further stressing the liver; it is still possible to revert back to a fatty liver or healthy liver at this stage
NASH with cirrhosis: advanced fibrosis, where the liver is severely scarred and permanently damaged; it is hardly possible to revert back to NASH with fibrosis, NASH, fatty liver, or a healthy liver
-
Compensated cirrhosis: when the liver is scarred but still able to perform most of its basic functions at some level, most people with compensated cirrhosis do not show symptoms
-
Decompensated cirrhosis: when the liver is scarred to the point where it can no longer perform its basic functions, most people with decompensated cirrhosis show symptoms of liver failure and will eventually need a transplant
Hepatocellular carcinoma (HCC): the most common form of primary liver cancer, occurs in the presence of continued inflammation