Metabolic Dysfunction Associated Steatohepatitis (MASH): Symptoms, Causes, Diagnosis, Treatment, and Prevention
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What Is Metabolic Dysfunction–Associated Steatohepatitis (MASH)?

What Is Metabolic Dysfunction–Associated Steatohepatitis (MASH)?
Everyday Health
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Updated on September 12, 2025
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What Is MASH?

Ira Breite, MD, a gastroenterologist at Mount Sinai Health System, discusses metabolic dysfunction–associated steatohepatitis (MASH).
What Is MASH?

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Metabolic dysfunction–associated steatohepatitis (MASH) is a progressive form of liver disease that occurs when there's an accumulation of fat in the liver.

MASH, which was formerly known as nonalcoholic steatohepatitis (NASH), is more common in people who have certain conditions associated with high blood lipid (fat) levels, such as type 2 diabetes and obesity. It is a more advanced stage of metabolic dysfunction–associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease (NAFLD).

For most people, MASH will never cause any symptoms. In a significant minority of severe cases, however, MASH can progress to cirrhosis, a level of scarring that causes a permanent loss of liver function and sharply raises the risk of liver cancer or liver failure. When the condition is diagnosed early, MASH's progression can be slowed, and even reversed, by medication and healthy lifestyle changes.

Stages of MASH

MASH is the second stage in a disease spectrum caused by excessive liver fat:

  • MASLD: The liver has accumulated an excess of fat. MASLD, which typically has no symptoms, is extremely common, affecting up to a quarter of American adults.
  • MASH: Excess fat has begun to cause inflammation and cell damage.
  • Fibrosis: Inflammation has caused scarring, and the liver begins to lose function.
  • Cirrhosis: Permanent scarring has seriously reduced the liver's ability to function, leading to symptoms and complications.
Only about 5 to 12 percent of people with MASH will ever experience cirrhosis. The odds of stopping or reversing this disease progression are greatly enhanced by early diagnosis and treatment.

Signs and Symptoms of MASH

Many people don't experience symptoms of MASH, particularly in the early stages. If symptoms do appear, they may initially be vague, including fatigue or pain in the right side of the abdomen.

As MASH progresses to cirrhosis, more distinct symptoms may accumulate, including:

  • Jaundice, or yellowing of the skin and eyes
  • Itching
  • Spider veins
  • Bruising and bleeding easily
  • Swelling of the abdomen (ascites)
  • Confusion, drowsiness, and slurred speech (hepatic encephalopathy)

Causes and Risk Factors of MASH

MASH is more likely to occur in people with metabolic syndrome, a group of warning signs associated with obesity.

 Metabolic syndrome is defined as the presence of three or more of the following conditions:

The condition is also more prevalent in people with conditions related to metabolic syndrome, such as obesity, type 2 diabetes, and obstructive sleep apnea. The risk increases with age.

How Is MASH Diagnosed?

If your doctor suspects you have liver disease, they'll run a series of tests that can identify liver damage. Because MASLD and MASH usually have no early symptoms, many people find out they have liver disease after routine blood tests detect an issue.

To diagnose MASH, tests may include the following:

  • Blood Tests A blood sample can help a doctor detect evidence of liver inflammation, including elevated liver enzymes. A lipid panel will indicate whether you have elevated levels of fat in your blood, while a fibrosis assessment test can identify fibrosis, or scarring. Additional blood tests may rule out other conditions.
  • Imaging Tests An abdominal ultrasound, CT scan, or MRI will allow your doctor to look at your liver and check for signs of inflammation, swelling, and scarring.
  • Liver Stiffness Tests These modified imaging tests measure stiffness and fibrosis levels in your liver.
  • Liver Biopsy The gold standard test to confirm a MASH diagnosis is a liver biopsy, although it's usually not needed if your doctor is able to find evidence of MASH through other testing measures. To perform a biopsy, your doctor will insert a small needle through your abdomen to collect a tissue sample from your liver.

Treatment and Medication Options for MASH

Lifestyle adjustments are the foundation of any MASH treatment plan. Until recently, no drug had been specifically indicated to treat MASH, but two new options can now treat the condition directly. If MASH progresses to cirrhosis, a liver transplant could become necessary, and additional medications will be required to manage disease symptoms and complications.

Medication Options

In the United States, there are two drugs approved for the treatment of MASH:

  • Resmetirom (Rezdiffra), a daily pill, can be prescribed to people with MASH who have moderate to advanced fibrosis. The drug activates a hormone in the liver that reduces inflammation and fat accumulation, reversing liver scarring.

  • Semaglutide (Wegovy), a weekly injection, can also be prescribed to people with MASH who have moderate to advanced fibrosis. The drug, which is also a blockbuster in the treatment of obesity and type 2 diabetes, promotes weight loss and other metabolic changes that reduce fat levels in the liver, leading to improvements in inflammation and reversal of scarring.

Both resmetirom and semaglutide are intended to be used in combination with lifestyle changes.

Though only two drugs are indicated for MASH, many people with the condition will be prescribed other drugs to control MASH risk factors such as diabetes, high blood pressure, and cholesterol.

If your condition progresses to cirrhosis, it is likely that you will need to take additional medications to help control the symptoms and side effects. Options could include:

  • Lactulose, a laxative to void toxic substances that your liver is no longer able to remove from the bloodstream
  • Diuretics to reduce fluid retention
  • Hypertension drugs to reduce blood pressure in the portal vein, the large vein attached to the liver
  • Cholesterol-lowering drugs to relieve itching

Liver Transplant

A liver transplant is the only treatment for the most advanced cases of liver disease. Unfortunately, there are more people who need a liver transplant than there are donors available. Doctors use a risk of death estimate to decide what priority potential transplant recipients have on the donation waiting list.

This is an intense procedure, and recipients will need to take anti-rejection drugs for the rest of their lives, but it can extend lifespan by years. About 75 percent of people who receive a liver transplant live another five years.

Lifestyle Changes for MASH

Lifestyle modifications are central to the treatment of liver disease, and are the only direct treatment for the many people who have not yet developed moderate fibrosis.

Expert recommendations for a healthy MASH lifestyle don't necessarily differ much from general health recommendations. That makes sense, because the development and progression of MASH is intimately linked to that of other lifestyle conditions such as diabetes, obesity, high blood pressure, high cholesterol, and heart disease.

  • Choose a heart-healthy diet, with plenty of vegetables, whole grains, minimally processed ingredients, and wholesome sources of fat and protein.
  • Try to reach the guidelines for physical fitness, which include both cardiovascular and strength-building exercises.
  • Reduce (or completely eliminate) alcohol and smoking.
  • Prioritize sleep quality and good mental health.
Your doctor may also advise you to limit or avoid certain over-the-counter medications and herbal supplements that are known to harm the liver, including acetaminophen (Tylenol).

Prevention of MASH

MASH is preventable using the same general lifestyle modifications that are recommended to help treat MASH and to prevent related conditions such as obesity, diabetes, and metabolic syndrome. Probably the most effective prevention is a healthy diet and physical activity to maintain a healthy weight.

Although MASLD is widespread, only about 13 percent of people with the condition also develop MASH.

MASH Prognosis

MASH does not necessarily have any effect on your quality of life or life expectancy. Most people with the condition will not develop advanced fibrosis or cirrhosis.

When scarring progresses to an advanced and irreversible stage, however, the loss of liver function can have a profound effect on long-term health. If cirrhosis is diagnosed and treated early, studies suggest that life expectancy may be an additional 10 to 15 years. If cirrhosis progresses to the point that it causes severe complications, such as internal bleeding, life expectancy may be as short as three to five years without a liver transplant.

 But every case of MASH is different, and these statistics cannot predict your prognosis or that of a loved one.

Complications of MASH

If you've been diagnosed with MASH, the primary worry is that liver fat and inflammation will lead to cirrhosis, irreversible liver damage. Only a minority of people with MASH will develop cirrhosis, a condition that has several potentially dangerous consequences:

  • Liver failure, which may require a liver transplant to be treated
  • Liver cancer, or hepatocellular carcinoma (HCC), a deadly form of cancer
  • Hepatic encephalopathy, a potentially life-threatening form of brain dysfunction that occurs when toxins build up in the blood
  • Portal hypertension, dangerously high blood pressure in the veins that connect to your liver and other parts of the digestive system

Research and Statistics: How Many People Have MASH?

Metabolic liver disease is extremely common, and rates are only growing hand in hand with the obesity and type 2 diabetes epidemics. The latest estimates suggest that the following numbers of American adults have developed some form of the condition:

  • MASLD: 86.3 million (33.7 percent of U.S. adults)
  • MASH: 14.9 million (5.8 percent)
  • Medically significant fibrosis: 6.7 million (2.6 percent)

Disparities and Inequities in MASH

In the United States, MASH appears to be most common among people of Hispanic descent, especially in men and those of Mexican origin. Some 45 percent of Hispanic adults have MASLD, compared with 33 percent of white adults and 24 percent of Black adults. Hispanic adults with MASLD are also more likely to progress to MASH and to more serious disease outcomes.

Experts believe that there is no one factor driving these disparities, but that they may instead be a result of genetics, environment, culture, and socioeconomic circumstances.

Related Conditions of MASH

MASH does not develop because of an isolated problem with the liver. Instead, it is one of many metabolic health conditions that are strongly associated with the same modifiable risk factors, including poor diet and lack of physical fitness, in addition to advanced age, genetics, and environmental factors. The following conditions may contribute to MASH because they may increase the amount of fat in the liver:

  • Obesity
  • Type 2 diabetes
  • Insulin resistance
  • Metabolic syndrome
  • High cholesterol
  • High triglycerides

Support for People With MASH

There are a number of organizations in America that can help educate and empower people with MASH.

American Liver Foundation

The American Liver Foundation (ALF) offers online resources and education, and hosts a Facebook support group for MASH to help you connect with others.

Community Liver Alliance

The Community Liver Alliance (CLA), which is based in Pittsburgh, develops videos and educational materials, hosts workshops, and coordinates support groups. They also help facilitate medical care and are a source of information on clinical trials testing experimental liver health therapies.

Global Liver Institute

The Global Liver Institute (GLI) is an advocacy group dedicated to raising awareness and promoting better treatment for liver conditions. They offer events and are eager to train new advocates for liver health, with an aim to bolstering research efforts and improving health policies.

The Takeaway

  • MASH is a progressive liver disease caused by the accumulation of fat in the liver and is often found in people with conditions like obesity and type 2 diabetes.
  • Early diagnosis and treatment of MASH can significantly slow or reverse the disease's progression.
  • If untreated, MASH can cause cirrhosis, which may lead to dangerous complications such as liver failure and liver cancer.
  • Lifestyle modifications, including a healthy diet and regular exercise, are crucial for managing MASH and preventing further liver damage.

Common Questions & Answers

Is MASH related to alcohol?

No. MASH is not caused by drinking alcohol, though your doctor may advise you to limit alcohol, or abstain completely, to keep from further stressing your liver.

In early stages, MASH can sometimes be reversed through lifestyle changes and certain medications. But advanced liver scarring is usually permanent.

MASH usually progresses slowly, and moving from one stage to another can take years. In some cases, however, MASH can develop and progress rapidly.

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
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  2. MASLD and MASH: Understanding the Basics: Disease Stages. Fatty Liver Alliance. January 13, 2025.
  3. MASLD and MASH* Symptoms. American Liver Foundation. June 12, 2025.
  4. MASH Causes & Risk Factors. American Liver Foundation. July 7, 2025.
  5. Kim Y et al. Metabolic Dysfunction-Associated Steatohepatitis Diagnosis and Management in Germany: Insights From an Expert Consensus Panel. Liver International. July 16, 2025.
  6. Azam MM et al. FDA's Approval of Resmetirom (Rezdiffra): A Breakthrough in MASH Management. Exploration of Drug Science. December 3, 2024.
  7. FDA Approves Treatment for Serious Liver Disease Known as ‘MASH'. U.S. Food and Drug Administration. August 15, 2025.
  8. Medications in Liver Disease. Irish Liver Foundation.
  9. Liver Transplant. Mayo Clinic. January 19, 2024.
  10. 8 Lifestyle Changes for MASH. Cleveland Clinic. February 26, 2025.
  11. Medications and the Liver. American College of Gastroenterology. August 2022.
  12. AACE Patient Guide to Metabolic Dysfunction–Associated Steatotic Liver Disease (MASLD) and Metabolic Dysfunction–Associated Steatohepatitis (MASH). American Association of Clinical Endocrinology.
  13. Non-Alcoholic Steatohepatitis (NASH): What Is It and Am I at Risk? University of Utah Health. June 9, 2023.
  14. Premkumar M and Anand AC. Overview of Complications in Cirrhosis. Journal of Clinical and Experimental Hepatology. May 14, 2022.
  15. Le P et al. Estimated Burden of Metabolic Dysfunction–Associated Steatotic Liver Disease in US Adults, 2020 to 2050. JAMA Network Open. January 17, 2025.
  16. Gulati R et al. Racial and Ethnic Disparities in Metabolic Dysfunction-Associated Steatotic Liver Disease. Metabolism and Target Organ Damage. February 25, 2024.
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Natalia Johnsen, MD

Medical Reviewer
Member of American College of Lifestyle Medicine

Natalia Johnsen, MD, practices internal medicine and lifestyle medicine. She works as an internist for the Vancouver Clinic in Vancouver, Washington.

Johnsen trained and worked as ob-gyn in Russia before coming to the United States in 2000. Subsequently, she interned in internal medicine at the University of Nevada and completed her residency at a Stanford-affiliated program in Santa Clara, California. After that she worked as a general internist for two years before to switching to full-time hospital work.

Johnsen has always been fascinated by the effects that lifestyle can have on physical and mental health, and she fell in love with the concept of lifestyle medicine as a specialty after seeing patients struggle with issues that could have been prevented had they known more about a healthy lifestyle. To make an impact on her patients through lifestyle interventions, she launched her own lifestyle medicine clinic, Vivalso Health and Longevity.

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Ashley Welch

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Ashley Welch has more than a decade of experience in both breaking news and long-form storytelling. She is passionate about getting to the crux of the latest scientific studies and sharing important information in an easy-to-digest way to better inform decision-making. She has written about health, science, and wellness for a variety of outlets, including Scientific American Mind, Healthline, New York Family, Oprah.com, and WebMD.

She served as the health editor for CBSNews.com for several years as a reporter, writer, and editor of daily health news articles and features. As a former staff member at Everyday Health, she covered a wide range of chronic conditions and diseases.

Welch holds a bachelor's degree from Fordham University and a master's degree from the Craig Newmark Graduate School of Journalism at the City University of New York, where she studied health and science reporting. She enjoys yoga and is an aspiring runner.

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