Key takeaways

  • Fatty liver is also known as hepatic steatosis. It happens when fat builds up in the liver. Having small amounts of fat in your liver is expected, but too much can become a health problem.
  • In most cases, fatty liver doesn’t cause symptoms until later stages. If you have symptoms, they’re likely to be vague, like abdominal pain and fatigue.
  • Treatment depends on the type and severity of fatty liver disease. Lifestyle changes, such as a balanced diet, more exercise, and limiting alcohol, usually help.

Your liver is the second-largest organ in your body. It helps process nutrients from food and drinks, and filters harmful substances from your blood.

Too much fat in your liver can cause liver inflammation, which can damage your liver and create scarring. In severe cases, this scarring can lead to liver failure.

When fatty liver develops in someone who drinks a lot of alcohol, it’s known as alcohol-associated liver disease (ALD).

In someone who doesn’t drink a lot of alcohol, it’s known as metabolic dysfunction–associated steatotic liver disease (MASLD), previously called nonalcoholic fatty liver disease (NAFLD).

This article explains everything you need to know about fatty liver diseases, including symptoms, types, causes, and treatments.

Fatty liver can progress through the following four stages:

  1. Fatty liver: There’s a buildup of excess fat in the liver. This stage is largely harmless if it doesn’t progress.
  2. Steatohepatitis: In addition to excess fat, there’s also inflammation in the liver.
  3. Fibrosis: Persistent inflammation in the liver has now caused scarring, called fibrosis. However, the liver can still generally function as it should.
  4. Cirrhosis: Scarring of the liver is widespread, irreversibly impairing liver function.

ALD and MASLD present similarly. However, in many cases, fatty liver causes no noticeable symptoms. But you may feel tired or experience discomfort or pain in the upper right side of your abdomen.

People may be more likely to notice symptoms during the later stages of fatty liver, including cirrhosis. The liver damage due to cirrhosis is permanent. That’s why it’s so important to prevent it from developing in the first place.

Cirrhosis may cause symptoms such as:

Below is more information about different types of fatty liver diseases.

Metabolic dysfunction–associated steatotic liver disease (MASLD)

If you have excess fat in your liver and no history of heavy alcohol use, you may receive a diagnosis of MASLD, formerly NAFLD.

Metabolic dysfunction-associated steatohepatitis (MASH) is a type of MASLD. It’s when you have a buildup of excess fat in the liver and inflammation. A doctor may diagnose MASH if:

  • you have excess fat in your liver
  • your liver is inflamed
  • you have no history of heavy alcohol use

Without treatment, MASH can cause liver fibrosis. In severe cases, this can progress to cirrhosis and liver failure.

Alcohol-associated liver disease (ALD)

Drinking a lot of alcohol damages the liver and may lead to ALD.

Alcohol-associated steatohepatitis (ASH) is when you have a buildup of excess fat in the liver and inflammation, which is also known as alcohol-induced hepatitis. A doctor may diagnose ASH if:

  • you have excess fat in your liver
  • your liver is inflamed
  • you drink a lot of alcohol

Without treatment, ASH can cause liver fibrosis and cirrhosis, which can lead to liver failure.

Acute fatty liver of pregnancy (AFLP)

AFLP is when excess fat builds up in the liver during pregnancy. It’s a rare but serious pregnancy complication. The exact cause is unknown, although genetics may be a reason.

When AFLP develops, it usually appears in the third trimester of pregnancy.

If a doctor diagnoses AFLP, they will want to deliver your baby as soon as possible. You might need to receive follow-up care for several days after you give birth.

Your liver health will likely return to typical within a few weeks of giving birth.

In fatty liver disease, your body stores excess fat in liver cells, where it accumulates. A variety of factors can cause this fat buildup.

Drinking too much alcohol can cause ALD. Heavy alcohol use can alter certain metabolic processes in the liver. Some of these metabolic products can combine with fatty acids, leading to the formation of types of fat that can accumulate in the liver.

In people who don’t drink a lot of alcohol, the cause of fatty liver disease is less clear. It’s possible their body produces too much fat or doesn’t metabolize fat efficiently enough.

One or more of the following factors may play a role in people who don’t consume much alcohol and develop fatty liver disease:

The above factors don’t guarantee someone will have fatty liver disease, but they may increase the risk. If you have one or more risk factors for fatty liver disease, talk with a doctor about prevention strategies.

The diagnosis process for a fatty liver may include the following:

  • Physical exam: To check for liver inflammation, a doctor may palpate or press on your abdomen. If your liver is enlarged, they might be able to feel it. However, it’s possible for your liver to be inflamed without being enlarged.
  • Blood tests: Blood tests may show elevated liver enzymes, which are a sign of liver inflammation. If doctors find elevated liver enzymes, they’ll likely order additional tests to identify the cause of the inflammation.
  • Imaging: A doctor may look at the liver using an ultrasound exam, a CT scan, or an MRI scan. They may also order a vibration-controlled transient elastography (VCTE, FibroScan), which uses low-frequency sound waves to measure liver stiffness.
  • Liver biopsy: A liver biopsy can help doctors diagnose MASH. Not everyone with fatty liver disease will need a biopsy.

Currently, experts do not approve any medications specifically to treat fatty liver disease. More research is necessary to develop and test drug treatments.

In many cases, lifestyle changes can help reverse most stages of fatty liver disease. For example, a doctor might advise you to:

  • limit or avoid alcohol
  • take steps to lose weight
  • make changes to your diet
  • avoid certain medications and supplements

If you have ALD, a doctor may recommend completely abstaining from alcohol. They may also recommend a detoxification program and counseling if you have alcohol use disorder.

Treating complications

Cirrhosis can also cause a variety of complications, including:

If you have complications from cirrhosis, a doctor might recommend additional treatments, such as medications or surgery.

Cirrhosis can also lead to liver failure. If you develop liver failure, you might need a liver transplant.

If you have fatty liver disease, a doctor might encourage you to adjust your diet to help treat the condition and lower your risk of complications.

The most suitable diet may depend on the type and stage of your liver disease. However, a doctor may suggest the following:

To prevent fatty liver disease and its potential complications, it’s important to follow a healthy lifestyle. Some general prevention tips include:

  • limiting or avoiding alcohol
  • maintaining a moderate weight
  • eating a nutrient-rich diet that’s low in saturated fat, trans fat, and refined carbohydrates
  • taking steps to manage your blood sugar, triglyceride levels, and cholesterol levels
  • following your recommended treatment plan for diabetes, if you have this condition
  • increasing the amount you exercise

Taking these steps can also help improve your overall health.

In many cases, it’s possible to reverse fatty liver disease through lifestyle changes, such as limiting alcohol, adjusting your diet, and managing your weight. These changes may help prevent further liver damage and scarring from occurring.

For ALD in particular, it’s important to abstain from alcohol use entirely. If you need help with not drinking alcohol, consider engaging in a detoxification program and counseling.

Without treatment, fatty liver disease can progress to inflammation, fibrosis, and cirrhosis. Scarring due to cirrhosis isn’t reversible. If you develop cirrhosis, it also increases your risk of liver cancer and liver failure. These complications can be life threatening.

Generally speaking, the outlook for fatty liver disease is best when treatment begins in the early stages, before fibrosis and cirrhosis.

For the best outcome, it’s important to follow a doctor’s recommended treatment plan and practice an overall healthy lifestyle.

Fatty liver disease is when excess fat accumulates in the liver. This can happen due to heavy alcohol use or other factors, such as metabolic syndrome.

Many people with fatty liver disease don’t experience significant symptoms until they have severe liver damage. When early symptoms are present, they can be nonspecific and include things like upper right abdominal pain and fatigue.

The main treatment for fatty liver disease is lifestyle changes that promote liver health. It’s possible to reverse the damage caused by fatty liver disease when it’s treated in its early stages.