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Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is a common disease of the liver. It occurs when there is too much fat in the liver. If NAFLD is severe, it can cause liver damage that seems like the damage caused by drinking too much alcohol. However, NAFLD is not caused by drinking alcohol. This sheet tells you more about NAFLD and how it can be managed.

Healthy liver, fatty liver, liver with cirrhosis

How the liver works


The liver is an organ located in the upper right side of the belly (abdomen). It has many important jobs. These include:

  • Breaking down (metabolizing) proteins, carbohydrates, and fats

  • Making a substance called bile that helps break down fats

  • Storing and releasing sugar (glucose) into the blood to give the body energy

  • Removing toxins from the blood

  • Helping with blood clotting

Understanding NAFLD

A healthy liver may contain some fat. But if too much fat builds up in the liver, this causes NAFLD. NAFLD can be mild, causing fatty liver. Or it can be more severe and show inflammation, as well as the fat, and cause non-alcoholic steatohepatitis (NASH).

  • Fatty liver. With fatty liver, the liver simply contains more fat than normal. This extra fat usually causes no damage to the liver.

  • NASH. With NASH, the fatty liver becomes inflamed over time. NASH is serious because it can lead to scarring of the liver (fibrosis). Over time, the scarring may lead to cirrhosis of the liver. This can eventually cause liver failure or liver cancer.

Causes and risk factors of NAFLD

The cause of NAFLD is unknown. But certain risk factors make the problem more likely to occur. These include:

  • Obesity

  • Prediabetes or diabetes

  • High levels of fat found in the blood (cholesterol and triglycerides)

  • Being exposed to certain medicines 

Symptoms of NAFLD

Most people with NAFLD have no symptoms. If symptoms do occur, they can include:

  • Tiredness

  • Weakness

  • Weight loss

  • Loss of appetite

  • Nausea and vomiting

  • Belly pain and cramping

  • Yellowing of the skin and eyes (jaundice), as well as dark urine, or light-colored stools

  • Swelling in the belly or legs

Diagnosing NAFLD

Your healthcare provider may think you have NAFLD if routine blood tests show high levels of liver enzymes. This may mean that a liver problem is possible. One or more imaging tests may be done, such as an ultrasound, CT, or MRI. Additional blood tests may be done to look for other causes of liver disease. A liver biopsy may also be done. During this test, a hollow needle is used to remove a tiny tissue sample from your liver. This tissue is then checked in a lab. This test can find signs of damage involving liver tissue. It can also help figure out the cause of the damage and tell the difference between fatty liver and NASH.

Treating NAFLD

Treatment for NAFLD varies for each person. The best early treatment is to treat any underlying conditions causing metabolic syndrome. This is the name for a group of conditions that includes:

  • High blood pressure

  • High levels of cholesterol and triglycerides

  • Being overweight or obese

  • Diabetes

Your healthcare provider will monitor your health and treat any symptoms or underlying health problems you have. Your provider will also work with you to control your risk factors so that damage to your liver is less likely. In fact, treating those underlying conditions can often improve liver disease. Certain medicines may be recommended, but no medicine will cure NAFLD. This is why treating the underlying conditions is most important. Your plan may include:

  • Losing extra weight

  • Getting regular exercise

  • Controlling diabetes and high cholesterol or triglyceride levels

  • Taking medicines and vitamins as prescribed by your provider

  • Quitting smoking

  • Not drinking alcohol

  • Eating a healthy and balanced diet

Living with NAFLD

If NAFLD is caught early, it can be managed with treatment. Your healthcare provider will discuss further treatment options with you as needed.

Online Medical Reviewer: Fetterman, Anne, RN, BSN
Online Medical Reviewer: Lehrer, Jenifer, MD
Date Last Reviewed: 12/1/2016
© 2000-2017 The StayWell Company, LLC. 780 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.