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Nonalcoholic Fatty Liver Disease (NAFLD) & NASH

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Definition & Facts

Nonalcoholic fatty liver disease (NAFLD) is a condition in which fat builds up in your liver. Nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH) are types of NAFLD. If you have NASH, you have inflammation and liver damage, along with fat in your liver.

doctor examining an obese patient

Symptoms & Causes

Usually, nonalcoholic fatty liver disease (NAFLD) is a silent disease with few or no symptoms. Certain health conditions—including obesity, metabolic syndrome, and type 2 diabetes—make you more likely to develop NAFLD.

Diagnosis

Doctors use your medical history, a physical exam, and tests to diagnose nonalcoholic fatty liver disease (NAFLD). Doctors may use blood tests, imaging tests, and liver biopsy to diagnose NAFLD and tell the difference between nonalcoholic fatty liver (NAFL) or nonalcoholic steatohepatitis (NASH).

Treatment

Doctors recommend weight loss to treat nonalcoholic fatty liver disease (NAFLD), which is either nonalcoholic fatty liver (NAFL) or nonalcoholic steatohepatitis (NASH). Weight loss can reduce fat, inflammation, and fibrosis in the liver. No medicines have been approved to treat NAFLD or NASH.

Eating, Diet, & Nutrition

You may be able to prevent nonalcoholic fatty liver disease (NAFLD)—nonalcoholic fatty liver (NAFL) or nonalcoholic steatohepatitis (NASH)—by eating a healthy diet and maintaining a healthy weight. If you have NAFLD, your doctor may recommend weight loss and diet changes.

Clinical Trials

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.

Related Conditions & Diseases

Related Diagnostic Tests

Your Digestive System & How it Works

The digestive system is made up of the gastrointestinal (GI) tract—also called the digestive tract—and the liver, pancreas, and the gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus.

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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.

The NIDDK would like to thank:
Brent A. Tetri, M.D., Saint Louis University