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 10% to 20% of Americans have NAFLD. About 2% to 5% have NASH.
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 developing 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 develop. If liver damage from NASH leads to permanent scarring and hardening of your liver, this is called cirrhosis.
Symptoms from NASH may include:
NASH that turns into cirrhosis could cause symptoms like fluid retention, internal bleeding, muscle wasting, and confusion. People with cirrhosis over time may develop liver failure and need a liver transplant.
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, and healthcare providers 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
When these risk factors happen together, they cause a condition called metabolic syndrome. Patients with metabolic syndrome often have fatty liver as well as a higher incidence of heart 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 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.
The diagnosis is often made without invasive testing. Imaging studies of your liver with ultrasound, CT scan, or MRI may show fat deposits, and in situations where the diagnosis is not certain, a liver biopsy may be done. 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 healthcare provider 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.
A special blood test can give your provider an idea of how diseased your liver is. This can often be done without needing a liver biopsy.
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 medicine, such as over-the-counter (OTC) medicines
If you have NASH, no medicine 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:
Medicine to reduce cholesterol or triglycerides
Medicine to reduce blood pressure
Medicine to control diabetes
Limiting OTC medicines
Seeing a liver specialist
Some medicines are recommended in patients with NASH. They have side effects that should be discussed first with your healthcare provider. These include Vitamin E and a diabetes medicine called pioglitazone. Other treatments, such as fish oil, are being studied.
The main complication of fatty liver disease is the progression of NASH to cirrhosis. Cirrhosis means permanent scarring and hardening of the liver.
When to call the healthcare provider
If you've been diagnosed with any fatty liver disease, let your healthcare provider know if you have any symptoms that mean the disease is getting worse. These include fatigue, loss of appetite, weight loss, weakness, fluid retention, or bleeding.
Living with fatty liver disease
If you are living with fatty liver disease, learn as much as you can about your condition and work closely with your medical team. Since many medicines can harm your liver, always let all your healthcare providers know 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 avoid alcohol.