Nonalcoholic Fatty Liver Disease

 Nonalcoholic Fatty Liver DiseaseNonalcoholic Fatty Liver Disease

Nonalcoholic Fatty Liver Disease


 

 

Terms You Should Know 

  • Cirrhosis : A condition in which scar tissue forms in the liver. 

  • Fatty Liver : Accumulation of fat within the cells of the liver. 

  • Hepatic : Pertaining to the liver. 

  • Hepatitis : Inflammation of the liver caused by viruses, medicines or toxins such as alcohol. 

  • Hepatomegaly : Enlargement of the liver. 

  • Liver : The largest internal organ in the body, the liver is located in the upper right portion of the abdomen. 

  • Overweight : Body mass index between 25 and 30.

  • Obesity : Body mass index of 30 or higher. 

Nonalcoholic fatty live disease (NAFLD) refers to a wide spectrum of liver diseases ranging from simple fatty liver ( steatosis) to nonalcoholic steato Hepatitis (NASH) to cirrhosis (irreversible, advanced scarring of the liver). All the stages of NAFLD have one common element - accumulation of fat ( fatty infiltration) in the liver cells (hepatocytes). In NASH, the fat accumulation is associated with varying degrees of inflammation ( Hepatitis) and scarring (fibrosis) of the liver. The term 'nonalcoholic' is used because NAFLD and NASH occur in individuals who do not consume excessive amounts of alcohol. 


The NAFLD spectrum is thought to begin with and progress from its simplest stage, called simple fatty liver ( steatosis). This involves accumulation of fat in the liver cells with no inflammation or scarring. Triglycerides accumulate in the liver cells. This accumulation of fat in the liver cells is not the same as the fat cells ( adipocytes) that constitute our body fat. Fatty liver is a harmless ( benign) condition, which means that by itself it does not cause any significant liver damage. 


The next stage and degree of severity in the NAFLD spectrum is NASH. Fortunately, only a fraction of patients with simple fatty liver develop NASH. NASH involves the accumulation of fat in the liver cells as well as inflammation of the liver. The inflammatory cells can destroy the liver cells ( hepatocellular necrosis). In the terms 'steatoHepatitis' and 'steatonecrosis', steato refers to fatty infiltration, Hepatitis refers to inflammation in the liver, and necrosis refers to destroyed liver cells. Strong evidence suggest that NASH, in contrast to simple fatty liver, is not a harmless condition. It can ultimately lead to scarring of the liver ( fibrosis) and then irreversible, advanced scarring (cirrhosis). Cirrhosis that is caused by NASH is the last and most severe stage in the NAFLD spectrum.


NAFLD affects more women than men and is found in all age groups, including children. Most often, it is a diagnosed in middle aged people who are overweight or obese, and who may also have diabetes and elevated cholesterol and triglyceride levels ( hyperlipidemia). As early-stage nonalcoholic fatty liver disease rarely causes any symptoms, it is usually detected because of abnormal results of liver tests done for unrelated issues. 

Causes and Risk Factors.
Complications and Treatment