Fatty Liver: Causes, Symptoms, and Treatment

Medically Reviewed by Jabeen Begum, MD on November 01, 2023
11 min read

Fatty liver disease (FLD) means you have extra fat in your liver. You might hear your doctor call it hepatic steatosis. Most of the time, it doesn't cause symptoms, but over time a buildup of fat makes it harder for your liver to work.



There are two main types of FLD:

1. Metabolic dysfunction-associated steatotic liver disease (MASLD)

This type used to be called nonalcoholic fatty liver disease (NAFLD). It is very common in the U.S., affecting 1 in 3 adults. Researchers aren't exactly sure what causes it, but having obesity or diabetes will increase your risk of getting it. Unlike the other main type, you don't get it from drinking alcohol. There are two forms of MASLD:

Simple fatty liver: This means you have fat in your liver, but you may not have any inflammation in your liver or damage to your liver cells. It usually doesn’t get worse or cause problems with your liver. Most people with MASLD have simple fatty liver.

Metabolic dysfunction-associated steatohepatitis (MASH): This used to be known as nonalcoholic steatohepatitis (NASH). It's the advanced stage of FLD and means you have inflammation in your liver. The inflammation and liver cell damage that happen with MASH can cause serious problems such as fibrosis and cirrhosis, which are types of liver scarring, and liver cancer. These problems can lead to liver failure and require a liver transplant. About 20% of people with MASLD have MASH.

2. Alcohol-related fatty liver disease (ALD)

This type is less common, affecting about 5% of people living in the U.S., and is caused by drinking alcohol. For this reason, it usually gets better if you stop drinking alcohol soon enough. If you keep drinking, ALD can cause serious problems that progress in stages: 

Enlarged liver. It doesn’t always cause symptoms, but you may have pain or discomfort on the upper right side of your belly.

Alcoholic hepatitis. This is swelling in the liver that can cause fever, nausea, vomiting, belly pain, and jaundice (yellowish skin and eyes).

Alcoholic cirrhosis. This is a buildup of scar tissue in your liver. It can cause the same symptoms as alcoholic hepatitis, plus:

  • Large amounts of fluid buildup in your belly (the doctor will call it ascites)
  • High blood pressure in the liver
  • Bleeding in your body
  • Confusion and changes in behavior
  • Enlarged spleen (a small organ inside your rib cage that's part of your immune system)
  • Liver failure, which can be fatal

Alcohol-related fatty liver disease usually comes first. It can then get worse and become alcoholic hepatitis. Over time, it may turn into alcoholic cirrhosis.

If you drink heavily, talk with your doctor. It’s confidential, and they can help you get your drinking under control to save your health.

With ALD and MASLD, there are usually no symptoms. Some people may have signs such as tiredness or pain in the upper right side of the belly where your liver is.

If you have MASH or get cirrhosis, you may have symptoms such as:

  • Swollen belly
  • Enlarged blood vessels underneath your skin
  • Larger-than-normal breasts in men
  • Red palms
  • Skin and eyes that appear yellowish, due to a condition called jaundice
  • Nausea, weight loss, or loss of appetite
  • Tiredness or mental confusion

For ALD, the cause is too much alcohol. You may be even more likely to get it if you drink a lot and

  • Have obesity
  • Are malnourished
  • Have chronic viral hepatitis, especially hepatitis C
  • Are Black or Hispanic and male or assigned male at birth
  • Are female or assigned female at birth, because of the way the bodies of these individuals process alcohol 
  • Are older – the older you are, the more likely it becomes

The reason why some people with MASLD have simple fatty liver and others get MASH isn’t known. Genes may be a reason. MASLD or MASH is more likely if:

  • You have obesity or are overweight
  • Your body doesn’t respond to insulin as it should (called insulin resistance) or if you have type 2 diabetes
  • You have high levels of triglycerides or “bad” (LDL) cholesterol, or low levels of “good” (HDL) cholesterol
  • You’re older
  • You have polycystic ovary syndrome
  • You have sleep apnea
  • You have an underactive thyroid (the doctor will call this hypothyroidism)
  • You have an underactive pituitary gland (you’ll hear this called hypopituitarism)
  • You’re malnourished
  • You’ve lost weight rapidly
  • You’ve been exposed to certain toxins and chemicals
  • You're Hispanic or Asian
  • You have metabolic syndrome. This is a mix of conditions that make you more likely to get type 2 diabetes and heart disease. With metabolic syndrome, you may have any three of these conditions:
    • Large waist size
    • High triglycerides or LDL cholesterol
    • Low levels of HDL (good) cholesterol
    • High blood pressure
    • High blood sugar

There are also some less common reasons why you may get MASLD or MASH. They include:

  • Medical conditions that affect how your body uses or stores fat
  • Hepatitis C or other infections
  • Fast weight loss
  • Taking certain medicines such as glucocorticoids, methotrexate (Rheumatrex, Trexall), synthetic estrogen, tamoxifen (Nolvadex, Soltamox), and others
  • Gallbladder removal. Some people who have surgery to remove their gallbladder are more likely to have MASLD.

Fatty liver disease and children

About 10% of children in the U.S. have MASLD – and numbers are growing as the number of kids who have obesity grows. MASLD is also more common in:

  • Older children rather than younger children
  • Hispanic and Asian American children rather than White and Black children (least common)
  • Boys rather than girls (though it's equally common among children with MASH)

But most children with MASLD don't get liver problems – and MASLD can be controlled or reversed if your child becomes more active and changes their eating habits.

Because most people don’t have symptoms, these conditions aren’t easy to diagnose.

Your doctor may use different methods to find out if you have fatty liver disease. Some of the things your doctor may use to diagnose fatty liver disease are:

Health history and physical exam 

Your doctor will ask about your alcohol use. This information can help your doctor tell if you have ALD or MASLD, so be truthful. They’ll also ask about medications you take, how you eat, and other health conditions you might have. Your doctor will also:

  • Check your body for signs of liver problems such as an enlarged liver or jaundice 
  • Check your height and weight to calculate your body mass index (BMI). Your BMI determines how much you should weigh based on your height.

Blood tests

Your doctor may order the following blood tests: 

  • Liver function and liver tests to detect and monitor liver disease and damage. The cells in your liver have proteins called enzymes. When these cells are damaged, the enzymes leak into your bloodstream, where they can be measured. If your liver is damaged, the level of these enzymes will be higher than normal.
  • Fibrosis assessment tests to estimate your level of liver scarring (fibrosis). These blood tests result in a score that estimates your level of liver scarring or fibrosis. 
  • Lipid profile to measure blood fats, such as cholesterol and triglycerides
  • Other blood tests to rule out other causes of FLD, like tests for hepatitis C and Wilson disease (a rare genetic condition)
  • Hemoglobin A1c, which shows how stable your blood sugar is

Imaging tests

You may get an ultrasound, computerized tomography (CT) scans, or magnetic resonance imaging (MRI). These tests can show if there’s any fat in your liver. But they can’t tell whether you have simple fatty liver or MASH. There are some tests that can show whether you have fibrosis by measuring the stiffness of your liver. When liver cells die, they're replaced by scar tissue, which is stiff. The stiffer your liver is, the more scarring it has.

  • Transient elastography measures liver stiffness using a special ultrasound machine.
  • Magnetic resonance elastography (MRE) combines ultrasound and MRI to create a visual map of stiffness throughout your liver. 

Liver biopsy

Not everyone with MASLD needs to have a liver biopsy. Your doctor may recommend it if you’re at risk for MASH or if other tests show that you may have MASH complications such as cirrhosis. A doctor removes a sample of tissue from your liver and sends it to a lab to see if you have liver inflammation or damage. You’ll get this done at a hospital or outpatient surgery center. Before the procedure, you’ll get medicine to help you relax or control pain. For the biopsy, your doctor numbs the area and uses a special needle to take a small piece of tissue from your liver. A liver biopsy is the only way for doctors to diagnose MASH.

Usually the first line of treatment is to lose weight. It helps reduce fat, inflammation, and scarring in your liver. Losing just 3% to 5% of your body weight can cut down on how much fat is in your liver. Weight loss surgery is also an option if you have a lot to lose.

One drug, remetirom (Rezdiffra), has been approved to treat MASH. You use it as part of a treatment plan that includes exercise and a healthy diet to lose weight. 

And whether you have MASLD or ALD, you’ll also need to not drink alcohol. You may be able to undo some of the liver damage that’s already happened. If you need to, talk to your doctor about how you can get help. You may need a medically supervised detox program to safely quit drinking and manage withdrawal symptoms.

If you have complications due to either type of FLD, such as cirrhosis or liver failure, you may need to have a liver transplant. In general, people with MASH who get a liver transplant do very well.

Fatty liver disease alternative treatments

Vitamin E. Studies have shown that vitamin E could improve liver health by reducing inflammation, but the results varied depending on the dosage, patient's age, and how overweight they were. Also, some studies showed that high does of vitamin E could be dangerous for people with other medical conditions as well as FLD.

Coffee. Caffeinated coffee has long been thought to be good for the liver and linked to slowing down liver scarring in various liver diseases. It's not clear how coffee prevents liver damage. One theory is that coffee activates enzymes that detoxify the liver. Another is that coffee has compounds that lower inflammation.

Olive oil. As a healthy fat, olive oil lowers the amount of fat stored in your liver, improves how your body deals with fats and sugars after a meal, and reduces inflammation. 

All of these methods are still being studied, so talk to your doctor or nutritionist before deciding to drink extra coffee daily or take extra olive oil or vitamin E.

Reversing fatty liver disease

FLD can be reversed if you avoid alcohol and take steps to get to a healthy weight. The liver is one of the few organs in your body that can replace damaged tissue with new cells rather than with scar tissue. But that reversal only works if you don't drink alcohol and follow a healthy lifestyle.

Lifestyle changes can help:

Exercise more. Try to be active at least 30 minutes a day most days of the week. If you're trying to lose weight, you might find that it helps to exercise more than this. But if you don't already exercise regularly, get your doctor's OK first and start slowly.

Be kind to your liver. Don’t do things that will make it work harder. Skip alcohol. Take medications and over-the-counter drugs only as instructed. Talk to your doctor before you try any herbal remedies. Just because a product is natural, that doesn’t mean it’s safe.

Get your cholesterol down. Eat a healthy plant-based diet, exercise, and take your medications. This will get – and keep – your cholesterol and your triglyceride levels where they need to be.

Manage your diabetes. Check your blood sugar, and take medications as your doctor prescribes.

Fatty liver disease diet. Changing the way you eat can help to lessen or reverse MASLD or MASH. You should try to:

  • Limit foods that are high in fats (such as sausage, bacon, cake, chocolate, etc.).
  • Replace saturated fats (such as butter, red meat, and cheese) with unsaturated fats (such as olive oil, salmon, and avocado).
  • Eat foods with a low glycemic index, such as fruits, vegetables, and whole grains.
  • Avoid foods and drinks with a lot of simple sugars (such as sweetened sodas, sports drinks, juices, and ice cream).
  • Follow a Mediterranean diet.

The main complication for all these conditions is cirrhosis. As your liver tries to stop the inflammation that comes with these conditions, it creates areas of scars. As inflammation spreads, so do the scars, and eventually, your liver can’t do its job. That can result in:

  • Fluid buildup in your belly
  • Swollen veins in your esophagus that can burst and bleed
  • Confusion and drowsiness
  • An overactive spleen
  • Liver cancer
  • Liver failure

If your liver has little or moderate scarring, it shouldn't affect your lifespan. But if you have cirrhosis, it could affect how long you live. If FLD cirrhosis is diagnosed early, you could live another 10 to 15 years. If it is diagnosed late or you have complications, like swelling or fluid in your belly or bleeding in the gut, your life expectancy could be 3 to 5 years unless you get a liver transplant.

To prevent ALD:

  • Drink in moderation. That’s one drink a day for men over 65 and women of all ages, and up to two drinks for men 65 and younger.
  • Protect yourself from hepatitis C. This viral liver infection can make you more likely to get cirrhosis if you drink.
  • Check before you mix meds and alcohol. Ask your doctor if it’s OK to drink alcohol with the prescription medications you’re taking. Read the warning label on over-the-counter meds. Don’t drink when you’re taking products like acetaminophen, which can damage your liver when combined with alcohol.

For MASLD and MASH, It boils down to making good choices:

  • Eat healthy food. Choose a plant-based diet with lots of fruits, vegetables, whole grains, and healthy fats.
  • Stay at a healthy weight. Lose weight if you need to. If your weight is healthy, work to maintain it by choosing a healthy diet and exercising.
  • Exercise. Get a workout most days of the week. Talk to your doctor first if you haven't been active in a while.

Fatty liver disease means you have a buildup of fat in your liver. One type of this condition is due to drinking alcohol. The other type, which is more common, doesn't have a specific cause, but things like having obesity and diabetes can increase your risk of getting it. Fortunately, you can reduce or even reverse liver damage by making lifestyle changes, like eating better and getting more exercise. With both types, you should not drink alcohol. 

Is fatty liver a serious problem?

Not for most people. But for 7% to 30% of the people with fatty liver disease, it will get worse if it is not treated.