Fatty liver disease is an illness marked by increased deposits of fat within the cells of the liver. Health care professionals use the term non-alcoholic fatty liver disease (NAFLD) to distinguish the condition when it is not caused by the consumption of alcohol. The liver processes and stores fat. Consuming excess alcohol can disrupt this process and lead to fatty liver disease. But in the case of NAFLD the excess fat is not caused by alcohol. NAFLD ranks as the most common cause of liver disease in the developed world. In the United States, up to 30 percent of Americans and about 90 percent of obese Americans suffer from NAFLD. Obesity is the condition of having excessive amounts of body fat.
There are two forms of NAFLD, called steatosis and non-alcoholic steatohepatitis (NASH). NASH describes the condition in which there is not only fat in the liver but also inflammation of the liver. About 20 percent of patients who develop NASH go on to develop cirrhosis. Cirrhosis is a condition marked by the formation of scar tissue throughout the liver (see Cirrhosis ). Steatosis describes the condition in which fat is found in the liver without inflammation. Steatosis is much less likely to progress to chronic liver disease and cirrhosis.
Medical experts do not know the exact cause of NAFLD. It is associated with certain conditions, especially diabetes, obesity, and with a related set of symptoms called metabolic syndrome. However, some people develop NAFLD even without these conditions. NAFLD occurs among all ethnic groups. It occurs more frequently in men. NAFLD is diagnosed mainly in adults. However, a dramatic increase in childhood obesity in the United States has caused a rise in the rate of pediatric (childhood) NAFLD.
Patients with NAFLD usually have no symptoms. When symptoms do occur, they include fatigue, malaise (discomfort), and abdominal pain. Doctors diagnose NAFLD using blood tests and imaging of the abdomen, such as ultrasound examination. An ultrasound examination involves imaging the body’s interior through the use of high-frequency sound. NASH is diagnosed using a liver biopsy (tissue sample). Treatments for NAFLD include weight loss and exercise.
