Non-Alcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH)
One of the most common causes of chronic hepatitis is the accumulation of excess fat in the liver. The condition develops gradually, typically over several years, with the intake of too many calories. Sometimes, the first sign is abnormal results on routine blood tests. A liver biopsy may be ordered in cases in which the liver is enlarged after viral or other causes of hepatitis have been ruled out. If the biopsy reveals that liver tissue is excessively fatty, inflamed, and showing signs of damage, the condition is called nonalcoholic steatohepatitis (NASH). If a fatty liver is otherwise healthy and showing no signs of inflammation or scarring, the condition is called non-alcoholic fatty liver disease (NAFLD). NASH can be severe and can lead to cirrhosis in the liver. NAFLD typically causes no long-term harm in most patients, although a small percentage will develop progressive liver damage.
These conditions are most commonly seen in people with metabolic syndrome, a combination of health problems such as obesity (especially too much fat in the belly), hypertension, high triglyceride levels, low HDL cholesterol, and insulin resistance or type 2 diabetes. Currently, there is no specific treatment for either condition; however, those affected are typically encouraged to reduce their weight by increasing physical activity and following a healthy diet.
Signs and symptoms are usually not apparent in people with hepatitis caused by non-alcoholic fatty liver disease. When present, the signs and symptoms are generally mild but may also correspond to those of hepatitis in general. See the section on Signs and Symptoms for detailed information.
A fatty liver may first be detected when routine tests such as a comprehensive metabolic panel (CMP) or a liver panel are performed for other reasons. Abnormal test results may be the first indication that there is a problem with the liver. Imaging tests such as ultrasound, CT scan, or MRI may detect some fat in the liver. Often, several laboratory tests are done to rule out other causes, such as alcohol or hepatitis C. However, there are no laboratory tests that can make the diagnosis of NAFLD or NASH other than a liver biopsy.
There is no specific treatment for non-alcoholic fatty liver disease. There are some things that can be done that often lead to improvement in the condition of the liver: