Fatty liver disease (hepatic steatosis): symptoms and causes
Fatty liver is the accumulation of triglycerides and other fats in the liver cells. The amount of fatty acid in the liver depends on the balance between the processes of delivery and removal. In some patients, fatty liver may be accompanied by hepatic inflammation and liver cell death (steatohepatitis).
Potential pathophysiologic mechanisms for fatty liver include the following:
Decreased mitochondrial fatty acid beta-oxidation
Increased endogenous fatty acid synthesis or enhanced delivery of fatty acids to the liver
Deficient incorporation or export of triglycerides as very low-density lipoprotein (VLDL)
No single pathway of cause and effect has been found. However, some studies show higher levels of activation of Hedgehog pathways in patients with the most advanced fatty liver disease.
Tripodi et al reported that in nonalcoholic fatty liver disease (NAFLD), a procoagulant imbalance progresses from steatosis to metabolic cirrhosis, which may be caused by an increase in factor VIII and a reduction of protein C. The investigators speculated that this imbalance could play a role in the risk for cardiovascular disease and liver fibrosis, conditions commonly associated with NAFLD.
Pathologic changes observed in patients with alcoholic liver disease (ALD) can be divided into the following 3 groups:
Alcoholic fatty liver (simple steatosis)
Symptoms of Fatty Liver Disease
You might have fatty liver disease and not realize it. There are often no symptoms at first. As time goes on, often years or even decades, you can get problems like:
Loss of weight or appetite
Confusion, poor judgment, or trouble concentrating
You might have some other symptoms, too. Your liver may get larger. You could have a pain in the center or right upper part of your belly. And the skin on your neck or under your arms may have dark, colored patches.
If you have alcoholic liver disease, you may notice that the symptoms get worse after a period of heavy drinking.
You could also get cirrhosis, a scarring of your liver. When that happens, you might have:
Buildup of fluid in your body
Wasting of your muscles
Bleeding inside your body
Jaundice (yellowing of skin and eyes)
Experts don’t know exactly why some people accumulate fat in the liver while others do not. Similarly, there is limited understanding of why some fatty livers develop inflammation that progresses to cirrhosis. Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis are both linked to the following:
Overweight or obesity
Insulin resistance, in which your cells don’t take up sugar in response to the hormone insulin
High blood sugar (hyperglycemia), indicating prediabetes or actual type 2 diabetes
High levels of fats, particularly triglycerides, in the blood
These combined health problems appear to promote the deposit of fat in the liver. For some people, this excess fat acts as a toxin to liver cells, causing liver inflammation and nonalcoholic steatohepatitis, which may lead to a buildup of scar tissue (fibrosis) in the liver.