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 normal, but too much can become a health problem.

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 alcoholic fatty liver disease (AFLD).

In someone who doesn’t drink a lot of alcohol, it’s known as non-alcoholic fatty liver disease (NAFLD). According to researchers in the World Journal of Gastroenterology, NAFLD affects up to 25 to 30 percent of people in the United States and Europe.

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.

Some people with fatty liver disease develop complications, including liver scarring. Liver scarring is known as liver fibrosis. If you develop severe liver fibrosis, it’s known as cirrhosis.

Cirrhosis may cause symptoms such as:

Cirrhosis is a potentially life-threatening condition. Get the information you need to recognize and manage it.

Fatty liver develops when your body produces too much fat or doesn’t metabolize fat efficiently enough. The excess fat is stored in liver cells, where it accumulates and causes fatty liver disease.

This build-up of fat can be caused by a variety of things.

For example, drinking too much alcohol can cause alcoholic fatty liver disease. This is the first stage of alcohol-related liver disease.

In people who don’t drink a lot of alcohol, the cause of fatty liver disease is less clear.

One or more of the following factors may play a role:

Less common causes include:

Certain genes may also raise your risk of developing fatty liver.

To diagnose fatty liver, your doctor will take your medical history, conduct a physical exam, and order one or more tests.

Medical history

If your doctor suspects that you might have fatty liver, they will likely ask you questions about:

  • your family medical history, including any history of liver disease
  • your alcohol consumption and other lifestyle habits
  • any medical conditions that you might have
  • any medications that you might take
  • recent changes in your health

If you’ve been experiencing fatigue, loss of appetite, or other unexplained symptoms, let your doctor know.

Physical exam

To check for liver inflammation, your 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. Your doctor might not be able to tell if your liver is inflamed by touch.

Blood tests

In many cases, fatty liver disease is diagnosed after blood tests show elevated liver enzymes. For example, your doctor may order the alanine aminotransferase test (ALT) and aspartate aminotransferase test (AST) to check your liver enzymes.

These tests might be recommended if you’ve developed signs or symptoms of liver disease, or they might be ordered as part of routine blood work.

Elevated liver enzymes are a sign of liver inflammation. Fatty liver disease is one potential cause of liver inflammation, but it’s not the only one.

If you test positive for elevated liver enzymes, your doctor will likely order additional tests to identify the cause of the inflammation.

Imaging studies

Your doctor may use one or more of the following imaging tests to check for excess fat or other problems with your liver:

They might also order a test known as vibration-controlled transient elastography (VCTE, FibroScan). This test uses low-frequency sound waves to measure liver stiffness. It can help check for scarring.

Liver biopsy

A liver biopsy is considered the best way to determine the severity of liver disease.

During a liver biopsy, a doctor will insert a needle into your liver and remove a piece of tissue for examination. They will give you a local anesthetic to lessen the pain.

This test can help determine if you have fatty liver disease, as well as liver scarring.

Currently, no medications have been approved to treat fatty liver disease. More research is needed to develop and test medications to treat this condition.

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

  • limit or avoid alcohol
  • take steps to lose weight
  • make changes to your diet

If you’ve developed complications, your doctor might recommend additional treatments. To treat cirrhosis, for example, they might prescribe:

  • lifestyle changes
  • medications
  • surgery

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

Lifestyle changes are the first-line treatment for fatty liver disease. Depending on your current condition and lifestyle habits, it might help to:

  • lose weight
  • reduce your alcohol intake
  • eat a nutrient-rich diet that’s low in excess calories, saturated fat, and trans fats
  • get at least 30 minutes of exercise most days of the week

According to the Mayo Clinic, some evidence suggests that vitamin E supplements might help prevent or treat liver damage caused by fatty liver disease. However, more research is needed. There are some health risks associated with consuming too much vitamin E.

Always talk to your doctor before you try a new supplement or natural remedy. Some supplements or natural remedies might put stress on your liver or interact with medications you’re taking.

If you have fatty liver disease, your doctor might encourage you to adjust your diet to help treat the condition and lower your risk of complications. For example, they might advise you to do the following:

  • Eat a diet that’s rich in plant-based foods, including fruits, vegetables, legumes, and whole grains.
  • Limit your consumption of refined carbohydrates, such as sweets, white rice, white bread, other refined grain products.
  • Limit your consumption of saturated fats, which are found in red meat and many other animal products.
  • Avoid trans fats, which are present in many processed snack foods.
  • Avoid alcohol.

Your doctor may encourage you to cut calories from your diet to lose weight. Learn more about some of the other dietary changes that might help you manage fatty liver disease.

There are two main types of fatty liver disease: nonalcoholic and alcoholic.

Nonalcoholic fatty liver disease (NAFLD) includes simple nonalcoholic fatty liver, nonalcoholic steatohepatitis (NASH), and acute fatty liver of pregnancy (AFLP).

Alcoholic fatty liver disease (AFLD) includes simple AFLD and alcoholic steatohepatitis (ASH).

Nonalcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) occurs when fat builds up in the liver of people who don’t drink a lot of alcohol.

If you have excess fat in your liver and no history of heavy alcohol use, your doctor may diagnose you with NAFLD.

If there’s no inflammation or other complications along with the build-up of fat, the condition is known as simple nonalcoholic fatty liver.

Nonalcoholic steatohepatitis (NASH)

Nonalcoholic steatohepatitis (NASH) is a type of NAFLD. It occurs when a build-up of excess fat in the liver is accompanied by liver inflammation.

If you have excess fat in your liver, your liver is inflamed, and you have no history of heavy alcohol use, your doctor may diagnose you with NASH.

When left untreated, NASH can cause scarring of your liver. In severe cases, this can lead to cirrhosis and liver failure.

Acute fatty liver of pregnancy (AFLP)

Acute fatty liver of pregnancy (AFLP) is a rare but serious complication of pregnancy. The exact cause is unknown.

When AFLP develops, it usually appears in the third trimester of pregnancy. If left untreated, it poses serious health risks to the mother and growing baby.

If you’re diagnosed with AFLP, your doctor 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 normal within a few weeks of giving birth.

Alcoholic fatty liver disease (ALFD)

Drinking a lot of alcohol damages the liver. When it’s damaged, the liver can’t break down fat properly. This can cause fat to build up, which is known as alcoholic fatty liver.

Alcoholic fatty liver disease (ALFD) is the earliest stage of alcohol-related liver disease.

If there’s no inflammation or other complications along with the build-up of fat, the condition is known as simple alcoholic fatty liver.

Alcoholic steatohepatitis (ASH)

Alcoholic steatohepatitis (ASH) is a type of AFLD. It happens when a build-up of excess fat in the liver is accompanied by liver inflammation. This is also known as alcoholic hepatitis.

If you have excess fat in your liver, your liver is inflamed, and you drink a lot of alcohol, your doctor may diagnose you with ASH.

If it’s not treated properly, ASH can cause scarring of your liver. Severe liver scarring is known as cirrhosis. It can lead to liver failure.

To treat alcoholic fatty liver, it’s important to avoid alcohol. If you have alcoholism, or alcohol use disorder, your doctor may recommend counseling or other treatments. Read more about the effects that alcohol can have on your body.

Drinking high amounts of alcohol puts you at increased risk of developing fatty liver.

You may also be at heightened risk if you:

If you have a family history of fatty liver disease, you’re more likely to develop it yourself.

Fatty liver can progress through four stages:

  • Simple fatty liver. There is a build-up of excess fat in the liver.
  • Steatohepatitis. In addition to excess fat, there is inflammation in the liver.
  • Fibrosis. Inflammation in the liver has caused scarring.
  • Cirrhosis. Scarring of the liver has become widespread.

Cirrhosis is a potentially life-threatening condition that can cause liver failure. It may be irreversible. That’s why it’s so important to prevent it from developing in the first place.

To help stop fatty liver from progressing and causing complications, follow your doctor’s recommended treatment plan.

To prevent fatty liver and its potential complications, it’s important to follow a healthy lifestyle.

  • Limit or avoid alcohol.
  • Maintain a healthy weight.
  • Eat a nutrient-rich diet that’s low in saturated fats, trans fats, and refined carbohydrates.
  • Take steps to control your blood sugar, triglyceride levels, and cholesterol levels.
  • Follow your doctor’s recommended treatment plan for diabetes, if you have it.
  • Aim for at least 30 minutes of exercise most days of the week.

Taking these steps can also help improve your overall health.

In many cases, it’s possible to reverse fatty liver through lifestyle changes. These changes may help prevent liver damage and scarring.

The condition can cause inflammation, damage to your liver, and potentially irreversible scarring if it’s not treated. Severe liver scarring is known as cirrhosis.

If you develop cirrhosis, it increases your risk of liver cancer and liver failure. These complications can be fatal.

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