According to the National Institute of Diabetes and Digestive and Kidney Diseases
Health Information Center, NASH is an acronym that stands for Non-Alcoholic SteatoHepatitis.
Usually, nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are silent diseases with few or no symptoms. You may not have symptoms even if you develop cirrhosis due to NASH.
If you do have symptoms, you may feel tired or have discomfort in the upper right side of your abdomen.
What causes NAFLD and NASH?
Experts are still studying the causes of NAFLD and NASH.
Research suggests that certain health conditions make you more likely to develop NAFLD or NASH.
Causes of NAFLD
You are more likely to develop NAFLD—either simple fatty liver or NASH—if you
have insulin resistance
have abnormal levels of fats in your blood, which may include
have metabolic syndrome or one or more traits of metabolic syndrome. Metabolic syndrome is a group of traits and medical conditions linked to overweight and obesity. People with metabolic syndrome are more likely to develop type 2 diabetes and heart disease. Experts think NAFLD may be closely linked to metabolic syndrome. Doctors define metabolic syndrome as the presence of any three of the following:
have type 2 diabetes
Research also suggests that certain genes may make you more likely to develop NAFLD. Experts are still studying the genes that may play a role in NAFLD.
In NAFLD, people have a buildup of fat in the liver that is not caused by alcohol use. If you have a history of heavy alcohol use and fat in your liver, your doctor may determine that you have alcoholic liver disease instead of NAFLD.
Causes of NASH
Experts are not sure why some people with NAFLD have NASH and others have simple fatty liver. Research suggests that certain genes may play a role.
People with NAFLD are more likely to have NASH if they have one or more of the following conditions:
obesity, especially with a large waist size
high blood pressure
high levels of triglycerides or abnormal levels of cholesterol in their blood
type 2 diabetes
Less common causes of NAFLD and NASH
Less common causes of NAFLD and NASH include
disorders that cause your body to use or store fat improperly
rapid weight loss
certain infections, such as hepatitis C
certain medicines, such as
exposure to some toxins
A study funded by the National Institute of Diabetes and Digestive and Kidney Diseases found that people who had surgery to remove their gallbladder were more likely to develop NAFLD. More research is needed on the link between gallbladder removal and NAFLD.
HOW IS NASH DIAGNOSED?
Doctors use blood tests, imaging tests, and sometimes liver biopsy to diagnose NASH.