Metabolic Dysfunction-Associated Steatohepatitis (MASH)

What is metabolic dysfunction-associated steatohepatitis?

Metabolic dysfunction-associated steatohepatitis (MASH) is a serious liver disease that develops when fat buildup in your liver causes inflammation. This condition was previously known as nonalcoholic steatohepatitis (NASH). Without treatment, MASH can lead to conditions like cirrhosis and liver cancer.

MASH is part of a broader group of liver diseases called MASLD (metabolic dysfunction-associated steatotic liver disease).

Conditions like obesity, Type 2 diabetes and high cholesterol increase your risk of developing MASH. If you have these conditions, ask your healthcare provider if you should have tests that may show signs of MASH.

What are MASH symptoms?

You may not have symptoms of MASH until it severely damages your liver. The condition develops slowly over the years. When you do have symptoms, they may include:

• Fatigue
• Discomfort or pain in your upper right belly
• Unexplained weight loss
• Muscle weakness or muscle loss
• Swollen belly or legs
• Yellowish tint to your eyes and skin (jaundice) as the condition worsens

Because early MASH often has no obvious symptoms, it’s important to get regular checkups — especially if you have risk factors like obesity, diabetes or high cholesterol.

What causes metabolic dysfunction-associated steatohepatitis?

MASH happens when too much fat builds up in the liver and causes inflammation. This is often linked to problems with how your body processes sugar and fat. Common causes and risk factors include:

• Obesity or overweight
• Type 2 diabetes
• High cholesterol
• High triglycerides
• High blood pressure
• Insulin resistance

You may develop MASH if you don’t have overweight but have issues like high cholesterol or high blood pressure.

What are the complications of MASH?

Without treatment, MASH can cause serious and potentially life-threatening complications, including:

• Liver fibrosis. Scarring in your liver that gets worse over time and leads to cirrhosis.
• Cirrhosis. Severe scarring that affects how your liver works. This is often permanent.
• Liver failure. Liver failure may happen suddenly, so you need immediate medical treatment or a liver transplant.
• Hepatocellular carcinoma. MASH increases your risk of this common liver cancer.
• Heart disease. The condition increases your risk of heart attack, stroke and other conditions that affect your heart.

How do healthcare providers diagnose MASH?

Diagnosing MASH involves several steps because it doesn’t cause symptoms right away. A healthcare provider will do a physical exam. They’ll ask if you have any conditions that increase your risk of developing MASH. They’ll do blood tests and imaging tests. They may do a liver biopsy.

Blood tests

Your provider will do blood tests to look for damage or inflammation in your liver. Tests may include:

• CBC
• BMP
• Lipid panel
• Hemoglobin A1C

Imaging tests

These tests provide images of your liver’s inside. Your provider will look for changes in your liver that could be signs of MASH. Imaging tests may include:

• CT scan
• Ultrasound
• FibroScan^®, a type of liver elastography
• Magnetic resonance elastography and proton density fat fraction (MRE-PDFF), which measures fat in your liver

Your provider may do a liver biopsy to get a small sample of your liver. A medical pathologist will cut the sample into tiny pieces. They’ll look at the sample under a microscope for signs of fat, inflammation and scarring. A liver biopsy is the most accurate way to diagnose MASH.

Your provider may do other tests to rule out other liver diseases that can cause your symptoms.

How is MASH treated?

MASH treatment focuses on improving your metabolic health and protecting your liver from further damage. Your treatment plan may include lifestyle changes, medication or bariatric surgery.

Lifestyle changes

Lifestyle changes to manage MASH include losing weight by eating well and becoming more active. Suggested lifestyle changes may include:

• Eating well. Good food plans for managing MASH include the Mediterranean diet or low-carb diet.
• Being active. Build up to 150 to 300 minutes of moderate-intensity aerobic exercise per week.
• Avoiding alcohol. Even drinking a small amount of alcohol puts stress on your liver.

Medication

Your provider may prescribe medications that reduce MASH symptoms like scarring. Examples are:

• Resmetiron (Rezdiffra^®). This drug may slow down or reverse the scarring in your liver that MASH can cause. It’s the only drug with U.S. Food and Drug Administration (FDA) approval to treat MASH with fibrosis stages 2 and 3.
• GLP-1 agonists. These drugs reduce inflammation and fat in your liver. Examples are liraglutide (Victoza^®, Saxenda^®) semaglutide (Ozempic^®, Wegovy^®) and tirzepatide (Mounjaro^®, Zepbound^®).

Your provider may prescribe other medications or supplements. For example, they may prescribe pioglitazone (Actoplus Met XR^®), which treats diabetes. They may recommend a supplement like vitamin E.

Researchers are studying new medications for MASH in clinical trials. Ask your provider if joining a trial might be a good option for you.

Bariatric surgery

Bariatric surgery may be a treatment option if you have obesity and advanced liver disease. Surgeries like gastric sleeve surgery or gastric bypass surgery can:

• Help you lose weight
• Improve or even reverse liver damage from MASH
• Dramatically reduce your risk of liver cirrhosis, liver cancer and needing a liver transplant

Is MASH curable?

MASH isn’t always curable. But early diagnosis and treatment may reverse the condition or keep it from getting worse.

What’s the life expectancy for someone with MASH?

Your life expectancy depends on how much damage MASH does to your liver. When caught early, many people live a normal lifespan with treatment. In more advanced stages, the risk of complications like liver failure, liver cancer or early death does increase — but treatment can still slow the disease and improve your quality of life. Starting care as soon as possible gives you the best chance for a better outcome.

When should I see my healthcare provider?

Seek care if you have symptoms like fatigue, pain in your upper right belly or unexplained weight loss. These are symptoms of issues with your liver. Your healthcare provider will do tests to find out if MASH is the cause or if you have other liver issues. Certain conditions increase the chance you’ll develop MASH. If you have conditions like obesity or type 2 diabetes, your provider may do tests to check on your liver.