Nonalcoholic fatty liver disease - what is it?

Nonalcoholic fatty liver disease (NAFLD) describes a range of conditions that affect people who drink little or no alcohol.

The mildest type is simple fatty liver (steatosis), an accumulation of fat within the liver that usually causes no liver damage. A potentially more serious type, nonalcoholic steatohepatitis (NASH), is associated with liver-damaging inflammation and, sometimes, the formation of fibrous tissue. In some cases, this can progress to either cirrhosis, which causes progressive, irreversible liver scarring, or to liver cancer.

Nonalcoholic fatty liver disease affects more women than men and is found in all age groups, including children. Most often, it's diagnosed in middle-aged people who are overweight or obese, and who may also have diabetes and elevated cholesterol and triglyceride levels (hyperlipidemia).

With the increasing incidence of obesity and diabetes in Western countries, nonalcoholic fatty liver disease has become a growing problem. Although its true prevalence is unknown, some estimates suggest it may already affect as many as one-third of American adults.

Because early-stage nonalcoholic fatty liver disease rarely causes any symptoms, it's usually detected because of abnormal results of liver tests done for unrelated issues. Preferred treatments include weight loss, exercise, improved diabetes control and the use of cholesterol-lowering medications. Research is under way to develop more specific treatments.