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, but that’s not the same as fatty liver disease.
Doctors 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 10 to 20 percent of Americans have NAFLD. About 2 to 5 percent have NASH.
Fatty liver disease is sometimes called a silent liver disease because it can occur without causing any symptoms. Most people with NAFLD live with fat in their liver without developing liver damage, but 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 develop. If liver damage from NASH leads to permanent scarring and hardening of your liver, this is called cirrhosis.
Symptoms from NASH may include:
Yellowing of the skin or eyes
Spiderlike blood vessels on the skin
NASH that turns into cirrhosis could cause symptoms like fluid retention, internal bleeding, muscle wasting, and confusion. People with cirrhosis may eventually develop liver failure and need a liver transplant.
Doctors 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, and doctors are seeing a steady rise in fatty liver disease. Although children and young adults can get fatty liver disease, it is most common in middle age.
Risk factors include:
Having high blood fat levels, either triglycerides or LDL (“bad”) cholesterol
Having diabetes or prediabetes
Having high blood pressure
Fatty liver disease can happen without causing any symptoms. It’s usually diagnosed when you have routine blood tests to check your liver. Your doctor may suspect fatty liver disease with abnormal test results, especially if you are obese. Drinking too much alcohol and having an infection may cause your liver tests to be abnormal.
Imaging studies of your liver may show fat deposits, but the only way to diagnose fatty liver disease is with 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 that can be looked at under a microscope. Here’s how your doctor makes the diagnosis:
If you have fat but no inflammation or tissue damage, the diagnosis is NAFLD.
If you have fat, inflammation, and liver damage, the diagnosis is NASH.
If you have a type of scar tissue in your liver called fibrosis, you may be developing cirrhosis.
If you have NAFLD without any other medical 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:
Lowering your cholesterol and triglycerides
Controlling your diabetes
Using medication, such as over-the-counter (OTC) drugs
If you have NASH, no medication is available to reverse the fat buildup in your liver. In some cases, the liver damage stops or even reverses itself. But in others, the disease continues to progress. If you have NASH, it’s important to control any conditions that may contribute to fatty liver disease. Treatments and lifestyle changes may include:
Medication to reduce cholesterol or triglycerides
Medication to reduce blood pressure
Medication to control diabetes
Limiting OTC drugs
Seeing a liver specialist
Some medications are being studied as possible treatments for NASH. These include antioxidants like vitamin E. Scientists are also studying some new diabetes medications for NASH that may be given even if you don't have diabetes.
The main complication of fatty liver disease is the progression of NASH to cirrhosis. Cirrhosis means permanent scarring and hardening of the liver.
If you've been diagnosed with any fatty liver disease, let your doctor know if you have any symptoms that mean the disease is progressing. These include fatigue, loss of appetite, weight loss, weakness, fluid retention, or bleeding.
If you are living with fatty liver disease, learn as much as you can about your condition and work closely with your medical team on your care. Since many medications can harm your liver, always let all your doctors know about any medications you are taking. These include OTC drugs, 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 avoid alcohol.