Non-alcoholic fatty liver disease is an umbrella term for a group of liver diseases that develop in people who drink very little alcohol. As the name suggests, the main feature of non-alcoholic fatty liver disease is a large amount of fat stored in the liver cells.
Non-alcoholic fatty liver disease is increasingly prevalent around the world, especially in Western countries. In the United States, it is the most common form of chronic liver disease, affecting about a quarter of the population.
Some people with nonalcoholic fatty liver disease may develop nonalcoholic steatohepatitis, which is a severe form of fatty liver disease characterized by inflammation of the liver and may progress to severe scarring (cirrhosis) and liver failure. This is similar to the harm caused by heavy alcohol consumption.
Usually, NAFLD does not show any signs or symptoms. When they do cause symptoms, they can include:
Pain or discomfort in the upper right part of the abdomen
Possible signs and symptoms of nonalcoholic steatohepatitis and advanced scarring (cirrhosis) include:
Enlargement of blood vessels under the surface of the skin
Redness of the palm
Yellowing of the skin and eyes (jaundice)
When should you see a doctor?
Make an appointment with your doctor if you have persistent signs and symptoms that worry you.
Experts don’t know exactly why some people accumulate fat in the liver while others don’t. Likewise, there is little understanding of why some people with fatty liver disease develop inflammation that progresses to cirrhosis.
Nonalcoholic fatty liver disease and nonalcoholic cirrhosis are associated with:
Overweight or obesity
Insulin resistance, which occurs when cells fail to absorb sugar in response to the hormone insulin
High blood sugar (hyperglycemia). This indicates the presence of prediabetes or type 2 diabetes
High levels of fats, especially triglycerides, in the blood
These can promote health problems associated with fat deposition in the liver. In some people, this extra fat acts as a poison to liver cells. It causes hepatitis and non-alcoholic steatohepatitis. This can lead to the development of scar tissue in the liver.