Fatty Liver Disease: Symptoms, Causes, Testing, Treatment

This guide covers fatty liver disease: its symptoms, causes, testing, and treatment. This guide explains that care in clear terms.

Fatty liver often causes no early symptoms ^1,5. Doctors may find it after abnormal blood work or imaging done for another reason ^6,10.

Newer names include MASLD and MASH. Older health records may use NAFLD and NASH instead ^3,5.

Early testing can confirm liver fat and estimate the risk of scarring ². Treatment often focuses on weight, activity, metabolic health, and the underlying cause ^5,10.

Steatotic liver disease is the newer name for fatty liver disease. It means too much fat has built up inside the liver ⁵.

The two main types are MASLD and alcohol-associated liver disease ⁵. Each type involves liver fat, but their main causes differ.

MASLD is linked to metabolic problems rather than heavy alcohol use ^3,5. Alcohol-associated liver disease results from heavy alcohol use ^3,5.

Metabolic dysfunction-associated steatotic liver disease is shortened to MASLD. It was previously called nonalcoholic fatty liver disease, or NAFLD ^2,3.

Simple fatty liver involves fat with little or no inflammation or liver damage ^3,5. This form is called nonalcoholic fatty liver (NAFL), also referred to as metabolic dysfunction-associated steatotic liver, or MASL ³.

MASH is a more serious form of MASLD. Its full name is metabolic dysfunction-associated steatohepatitis ^3,5.

MASH was previously called nonalcoholic steatohepatitis, or NASH ^3,5. It includes liver fat, inflammation, and damage to liver cells ^3,5.

Fat buildup alone does not show how much liver damage is present ². Some people later develop inflammation and fibrosis, which means liver scarring ³.

Ongoing inflammation can lead to cirrhosis, which is severe and lasting liver scarring ^3,7. Cirrhosis can limit how well the liver works ^6,7.

Advanced cirrhosis may lead to liver failure ^3,7. A liver transplant may become necessary when the liver can no longer function ^3,5.

Progression is not the same for every person. Many people with MASLD have a good outlook, especially with recommended lifestyle changes.

MASLD commonly causes few or no symptoms ^1,5. It may remain unnoticed until routine tests suggest a liver problem.

A yearly blood test may show raised liver enzymes. Imaging for another concern may also reveal fat inside the liver ⁶.

Symptoms cannot confirm fatty liver on their own. Several liver and health problems can cause similar symptoms.

If symptoms occur, they may be mild and hard to identify. Possible MASLD symptoms include the following:

These symptoms do not reveal whether scarring is present. Testing is needed to assess inflammation and liver damage ².

More serious signs can appear when MASH progresses to cirrhosis. These signs include:

Other signs, such as jaundice or belly swelling, may appear as fatty liver disease worsens ^6,7. They need medical assessment rather than self-diagnosis.

Experts do not fully know why some people develop liver fat. MASLD has strong links with insulin resistance and other metabolic conditions.

Insulin resistance means cells do not respond well to insulin. This problem can raise blood sugar and contribute to metabolic stress.

Common conditions linked with MASLD include the following:

MASLD can still occur without obesity or clear risk factors. It can affect adults, young people, and children ^3,8.

Alcohol-associated liver disease is separate from MASLD. Heavy alcohol use causes this form of fatty liver ^3,5.

A clinician will ask about current and past alcohol use during diagnosis ². This history helps identify whether alcohol may explain the liver fat ².

Metabolic risk factors and alcohol use can occur together in steatotic liver disease ⁶. For this reason, give your care team an honest account of alcohol use.

Several other health issues and exposures may contribute to liver fat. Possible contributors include:

Do not stop a prescribed medicine without guidance from your clinician ⁵. Your clinician may change a medicine if it appears to be contributing ⁵.

MASH is more likely among people over age 50. It is also more likely with obesity, diabetes, or metabolic syndrome.

People with MASLD also face higher risks of heart and metabolic problems ³. These higher-risk problems include cardiovascular disease, type 2 diabetes, and conditions such as high blood pressure ³.

Fatty liver tests begin with a medical history and physical examination ^2,5. Your clinician will ask about alcohol, medicines, diet, activity, and metabolic conditions ².

The examination may include these checks:

These steps help guide further testing. They cannot show the exact amount of inflammation or scarring.

Blood tests can check liver health and related metabolic risks. Common tests include:

High ALT or AST levels may raise suspicion for MASLD ². However, diagnosis also requires history, examination, and other tests ².

Clinicians may calculate FIB-4 or APRI from routine laboratory results ². These scores help identify or rule out advanced fibrosis ².

A score does not directly view the liver. It helps the clinician decide whether more fibrosis testing is useful.

Routine imaging can show fat inside the liver ². An abdominal ultrasound is often the first imaging test used.

Other imaging choices include the following:

Routine ultrasound, CT, and MRI cannot reliably separate simple fat from MASH ². These scans do not show the inflammation needed to prove MASH ².

Elastography helps estimate whether advanced fibrosis may be present ². Greater stiffness may be a sign of liver scarring ².

A liver biopsy removes a small tissue sample for examination under a microscope ². It can confirm MASH (previously called NASH) and show how severe the disease is ².

Biopsy can show inflammation, liver-cell damage, and fibrosis ^2,10. It can also detect earlier fibrosis than elastography ².

Most people with suspected MASLD do not need a biopsy ². A clinician may suggest one when other results are unclear.

Biopsy may also help when tests suggest advanced disease ². It can exclude other liver conditions in selected cases ².

A liver specialist may be useful when fibrosis risk is high. Specialist care may also help when the diagnosis remains uncertain.

Fatty liver treatment often starts with gradual weight loss. Losing weight can reduce liver fat, inflammation, and fibrosis ¹.

Losing about 3% to 5% of starting weight may provide health benefits. Your care team can help you choose a gradual and realistic plan.

Rapid weight loss is not the goal. Rapid loss is listed as a possible contributor to fatty liver ⁵.

A healthy diet can support weight and metabolic health. Food choices should emphasize suitable portions and less added sugar.

Helpful eating steps include the following:

A diet plan should fit your health needs and food preferences. A clinician or dietitian can help you build that plan.

Regular exercise can reduce liver fat and support weight loss ⁵. Mayo Clinic advises aiming for at least 150 minutes each week.

Start slowly if you are not active now. Get approval from your healthcare team before beginning a new exercise plan.

Daily movement can also support blood sugar, blood pressure, and cholesterol control. Your care plan may combine activity with medicines for these conditions.

Good metabolic control is a central part of fatty liver treatment. Care may address these conditions:

If stopping alcohol is difficult, support is available. Counseling, recovery programs, and certain medicines may help ⁵.

The FDA approved new medicines for liver inflammation and scarring during 2024 and 2025 ⁶. Two medicines are available for MASH with moderate to severe scarring.

Those medicines are resmetirom and semaglutide. They can reduce liver fat and scarring in eligible patients.

These medicines are not recommended for people with cirrhosis. Treatment choice depends on the diagnosis and degree of liver scarring.

Ask your prescriber to review the latest FDA indications and contraindications. The current label should guide each treatment decision.

Check with your healthcare team before using herbal supplements. Some supplements can harm the liver.

Follow all instructions for prescription and nonprescription medicines. Do not stop taking medicines unless your care team tells you to ⁵.

People with chronic liver disease may need added protection from infections ⁵. A clinician may recommend these vaccines:

Cirrhosis complications may require medicines, procedures, or surgery ⁵. Liver failure caused by cirrhosis may require transplantation ^3,5.

Ask your clinician how often you need blood tests or fibrosis checks. The answer should reflect your current liver findings and health risks.

Fatty liver may be found before symptoms appear ^6,10. Discuss abnormal liver tests or unexpected liver fat with a healthcare professional.

If fatigue or upper-right abdominal discomfort continues, ask for an assessment. These symptoms can occur with fatty liver but are not specific ^5,8.

If jaundice, belly swelling, leg swelling, or confusion appears, arrange medical assessment. These signs can occur with advanced liver disease ^6,7. New or worsening confusion, disorientation, or excessive drowsiness in someone with known or suspected advanced liver disease needs emergency evaluation — go to an emergency department or call emergency services right away.

Testing can determine whether liver fat, inflammation, or dangerous scarring is present ². Do not rely on symptoms or liver enzymes alone.

Fatty liver is often silent, but testing can reveal fat and estimate scarring risk ^1,2. Blood scores, imaging, elastography, and selected biopsies each provide different information ².

Lifestyle care remains central to treatment ^5,10. Gradual weight loss, regular activity, and metabolic control can support liver health ^1,10.

Understanding the symptoms, causes, tests, and treatments can help you take informed action. It can also help you recognize signs linked with advanced disease.