Fatty Liver Disease

Medically Reviewed By William C. Lloyd III, MD, FACS
Was this helpful?

What is fatty liver disease?

Fatty liver disease is a buildup of fats in the liver. The liver is the largest internal organ and has many functions. This includes aiding with digestion, storing energy, and metabolizing—or breaking down—fats, carbohydrates, proteins and drugs. Normally, it stores a small of amount of fat. Fatty liver occurs when the amount of stored fat exceeds 5 to 15% of the liver’s weight. The medical name for this is steatosis.

There are two types of fatty liver disease:

  • Alcoholic fatty liver disease is due to heavy alcohol use, typically over many years. When you drink alcohol, the liver breaks it down so your body can get rid of it. In the process, harmful by-products damage liver cells. The damage increases with more and more alcohol use. Fatty liver disease is the earliest form of alcoholic liver disease. With continued alcohol intake, it can progress to hepatitis and then cirrhosis, which is scarring of the liver.

  • Nonalcoholic fatty liver disease (NAFLD) is not related to alcohol use. The cause of this form is unclear. NAFLD is the most common type of chronic liver disease in the United States. There are two forms of NAFLD. The first is simple fatty liver—fat has built up, but there is no inflammation or liver damage. The more serious form is nonalcoholic steatohepatitis (NASH)—inflammation and damage are present and can lead to cirrhosis or liver cancer.

Alcoholic fatty liver disease only affects people who drink large amounts of alcohol. NAFLD tends to occur in people with obesity and conditions related to obesity, such as type 2 diabetes. The risk increases with age.

Both forms of fatty liver disease usually do not have symptoms. Sometimes, people with fatty liver disease experience fatigue or discomfort or pain in the upper abdomen. Because there are no specific symptoms early on that would involve medical care, doctors often find fatty liver disease when blood tests or imaging exams for other reasons reveal a problem.

Fatty liver disease treatment depends on the type of disease. The best treatment for alcoholic fatty liver disease is to stop drinking alcohol. Weight loss is the most effective treatment for NAFLD. Liver transplant may be an option for some people with NASH. Left untreated, fatty liver disease can lead to cirrhosis and liver failure.

What are the symptoms of fatty liver disease?

In most cases, fatty liver disease is a silent disease, meaning it doesn’t have symptoms. When fatty liver disease symptoms occur, they tend to be vague. Signs and symptoms may include fatigue, enlarged liver, and upper abdominal pain, fullness or discomfort.

Common symptoms of NASH and cirrhosis

If fatty liver disease progresses to NASH or cirrhosis, symptoms can include:

Because symptoms are usually absent, fatty liver disease often shows up during testing for other reasons. Doctors may find it when routine blood tests show problems with liver function or during imaging exams for other conditions. Regular medical care can help uncover any potential liver problems early, when it may be possible to protect the liver.

What causes fatty liver disease?

Heavy alcohol consumption is the cause of alcoholic fatty liver disease. For women, this means more than one drink per day on average. In men, it’s more than two drinks per day on average.

The cause of NAFLD is not entirely clear. Doctors can’t predict who will accumulate fat in their liver and who will not. They also can’t tell who will go on to develop more severe liver disease and cirrhosis. However, there seems to be a link between NAFLD and other conditions. This includes obesity, type 2 diabetes, metabolic syndrome, and high blood triglyceride levels.

What are the risk factors for fatty liver disease?

In addition to obesity and metabolic syndrome, a number of factors increase the risk of developing NAFLD including:

The risk of NAFLD progressing to NASH (hepatitis and liver cell damage from fat) is higher in older people, people with type 2 diabetes, and those with fat accumulation in the abdomen.

Reducing your risk of fatty liver disease

You may be able to lower your risk of a disease by changing risk factors that are under your control. For alcoholic fatty liver disease, this means limiting or avoiding alcohol consumption. For NAFLD, the main focus is healthy living including:

  • Eating a healthy diet with plenty of fresh fruits and vegetables, whole grains, and healthy fats

  • Getting physical exercise on most days of the week

  • Maintaining a healthy body weight

If you have risk factors for fatty liver disease, talk with your doctor about ways to reduce your risk. Ask about appropriate exercise and weight goals for you. If you need help reaching those goals, consider working with a registered dietitian or personal trainer.

How is fatty liver disease treated?

There are no medicines with specific indications to treat fatty liver disease. However, this is an active area of research. Instead, fatty liver disease treatment focuses on managing the underlying cause and related conditions. For alcoholic fatty liver disease, this means stopping alcohol use. This is often easier said than done. Most people need help giving up alcohol for good. Talk with your doctor and find a recovery program that will meet your needs.

For NAFLD, the treatment goal is weight loss. The ideal amount of weight to lose is usually around 10% of your starting weight. But even more modest weight loss of 3 to 5% can be beneficial. Losing body weight will reduce the amount of fat in your liver and help manage many of the conditions related to NAFLD. If your NAFLD is related to another cause, such as a medicine, your doctor will address it as well.

Your doctor will also likely recommend a fatty liver disease diet as part of your treatment. It will help you lose weight and protect your liver by eliminating unhealthy fats from your diet. In general, this diet is low in fat overall. It also replaces saturated and trans fats with unsaturated fats and omega-3 fatty acids. It limits simple sugars and high-glycemic index foods as well.

When NAFLD progresses to NASH and cirrhosis, liver transplantation may be an option.

What are the potential complications of fatty liver disease?

The main complication of fatty liver disease is cirrhosis, which is scarring of the liver. About 20% of people with NASH will go on to develop cirrhosis. Cirrhosis is permanent and irreversible damage that keeps the liver from working normally. Cirrhosis also increases the risk of liver cancer.

Was this helpful?
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jun 1
View All Liver Conditions Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Cirrhosis. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/liver-disease/cirrhosis/definition-facts
  2. Fatty Liver Disease. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/15831-fatty-liver-disease
  3. Fatty Liver Disease. U.S. National Library of Medicine. https://medlineplus.gov/fattyliverdisease.html
  4. Nonalcoholic Fatty Liver Disease. Mayo Foundation for Medical Education and Research. https://www.mayoclinic.org/diseases-conditions/nonalcoholic-fatty-liver-disease/symptoms-causes/syc-20354567
  5. Nonalcoholic Fatty Liver Disease and NASH. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash/definition-facts