What is nonalcoholic fatty liver disease?

Nonalcoholic fatty liver disease is a buildup of fat in the liver that is not caused by drinking alcohol.

What causes it?

There is no definite cause, but it may be related to obesity and a lack of exercise. Obesity can make it hard for the body to respond to insulin, which is a hormone that helps the body make energy. This causes other health problems like diabetes, high blood pressure, and high cholesterol. These problems increase the risk of a heart attack.

How do I know if I have it?

Most people with nonalcoholic fatty liver disease do not know they have it. There are usually no symptoms. Your doctor can do tests to check your liver. There are three main tests: blood tests, radiology tests, and liver biopsy. Blood tests check the liver for injury, and can rule out other conditions that cause liver disease.

Radiology tests take pictures of your liver to check for fat and to rule out other diseases. The most common radiology test is an ultrasound, which uses sound waves and is painless. Two other radiology tests are computed tomography (CT) and magnetic resonance imaging (MRI). For a CT scan, your doctor may give you a special dye to help see certain areas of your body. The dye may be given orally, rectally, or through an IV.

Liver biopsy is the best way to diagnose certain kinds of liver disease, but it is not usually needed. Your doctor will decide if you need a liver biopsy.

How is it treated?

It is treated with a healthy diet, exercise, and weight loss. Over-the-counter omega-3 fatty acids, vitamin E, and some prescription medicines also may be helpful. Weight loss surgery (gastric bypass or bariatric surgery) may be helpful, but more research is needed to prove this.

How do I prevent other diseases?

Exercising regularly and keeping a healthy weight are important. Your doctor may recommend getting shots for hepatitis A and B. You should also limit how much alcohol you drink to prevent alcohol-related liver disease.

What else should I know?

Most people with nonalcoholic fatty liver disease will not get chronic liver disease. It will not increase the risk of death. Rarely, it can lead to more serious liver problems.