Health Library

Nonalcoholic Fatty Liver Disease

Fatty liver disease means that you have fat deposits inside your liver. These deposits may keep your liver from doing a good job of removing toxins from your blood. People who drink too much alcohol may also have fat in their liver. When the fatty liver does not come from drinking too much alcohol, it is called nonalcoholic fatty liver disease. 

Types of fatty liver disease

Healthcare providers divide fatty liver disease into two types. If you just have fat but no damage to your liver, the disease is called nonalcoholic fatty liver disease (NAFLD). If you have fat in your liver plus signs of inflammation and liver cell damage, the disease is called nonalcoholic steatohepatitis (NASH).

About 1 in 10 to 1 in 5 Americans has NAFLD. About 1 in 50 to 1 in 20 has NASH.

Symptoms of fatty liver disease

Fatty liver disease is sometimes called a silent liver disease. This is because it can happen without causing any symptoms. Most people with NAFLD live with fat in their liver without getting liver damage. A few people who have fat in their liver develop NASH.

If you have NASH, you may have symptoms. But it could take years for them to show up. Sometimes liver damage from NASH causes long-term (permanent) scarring and hardening of your liver. This is called cirrhosis.  

Symptoms from NASH may include:

  • Severe tiredness

  • Weakness

  • Weight loss

  • Yellowing of the skin or eyes

  • Spiderlike blood vessels on the skin

  • Long-lasting itching

NASH that turns into cirrhosis could cause symptoms such as retaining extra fluid, internal bleeding, muscle wasting, and confusion. People with cirrhosis over time may develop liver failure and need a liver transplant.

Who is at risk for fatty liver disease?

Healthcare providers don’t know the exact cause of fatty liver disease. But they think that obesity is the most common cause. Obesity in the U.S. has doubled in the last decade. Healthcare providers are seeing a steady rise in fatty liver disease. Children and young adults can get fatty liver disease, but it is most common in middle age. 

Risk factors include:

  • Being overweight

  • Having high blood fat levels. This is either triglycerides or LDL (“bad”) cholesterol.

  • Having diabetes or prediabetes

  • Having high blood pressure

When these risk factors happen together, they cause a condition called metabolic syndrome. People with metabolic syndrome often have fatty liver. They also are more likely to have heart disease. 

Diagnosing fatty liver disease

Fatty liver disease can happen without causing any symptoms. It’s usually diagnosed when you have routine blood tests to check your liver. Your healthcare provider may suspect fatty liver disease if your test results are abnormal. This is especially true if you are obese. Drinking too much alcohol and having an infection may cause your liver tests to be abnormal.

Your provider often makes the diagnosis by using imaging tests of your liver. Ultrasound, CT scan, or MRI may show fat deposits. If your provider isn't sure about the diagnosis, you may need a liver biopsy. A liver biopsy involves putting a long needle through your skin into your liver. The needle removes a small piece of liver tissue. The tissue can be looked at under a microscope.

Here’s how your healthcare provider makes the diagnosis:

  • The diagnosis is NAFLD if you have fat but no inflammation or tissue damage.

  • The diagnosis is NASH if you have fat, inflammation, and liver damage.

  • You may be developing cirrhosis if you have a type of scar tissue in your liver called fibrosis.

A special blood test can give your provider an idea of how diseased your liver is. This can often be done without a liver biopsy.

Treatment for fatty liver disease

If you have NAFLD without any other health problems, you don’t need any special treatment. But making some lifestyle changes can control or reverse the fat buildup in your liver. These may include:

  • Losing weight

  • Lowering your cholesterol and triglycerides

  • Controlling your diabetes

  • Using medicine, such as over-the-counter (OTC) medicines

  • Not drinking alcohol

If you have NASH, no medicine is available to reverse the fat buildup in your liver. Sometimes the liver damage stops or even reverses itself. But for other people, the disease continues to get worse. If you have NASH, it’s important to control any conditions that may contribute to fatty liver disease. Treatments and lifestyle changes may include:

  • Losing weight

  • Exercising more

  • Taking medicine to reduce cholesterol or triglycerides

  • Taking medicine to reduce blood pressure

  • Taking medicine to control diabetes

  • Limiting OTC medicines

  • Not drinking alcohol

  • Seeing a liver specialist

You may need to take certain medicines if you have NASH. These include vitamin E and pioglitazone, a diabetes medicine. These have side effects so discuss them with your healthcare provider. Researchers are studying other treatments such as fish oil. 

Complications of fatty liver disease

The main complication of fatty liver disease is that NASH can become cirrhosis. Cirrhosis means permanent scarring and hardening of the liver.

When to call your healthcare provider

Call your healthcare provider if you have any symptoms that mean fatty liver disease is getting worse. These include fatigue, loss of appetite, weight loss, weakness, retaining extra fluid, and bleeding.

Living with fatty liver disease

If you have fatty liver disease, learn as much as you can about your condition. Work closely with your medical team. Because many medicines can harm your liver, always tell all of your healthcare providers about any medicines you are taking. These include OTC medicines, dietary supplements, and vitamins.

Other ways to manage fatty liver disease include maintaining a healthy weight, eating a balanced diet, getting regular exercise, and continuing to not drink alcohol.

Be sure to ask your healthcare provider about recommended vaccines. These include vaccines for viruses that can cause liver disease.