Metabolic Dysfunction-Associated Steatohepatitis (MASH)

What is metabolic dysfunction-associated steatohepatitis?

Metabolic dysfunction-associated steatohepatitis is fat accumulation that causes persistent inflammation and damage to liver cells in this progressive liver disease. It’s part of a broader group of disorders known as nonalcoholic fatty liver disease, which affects millions worldwide.

This condition was once called NASH (nonalcoholic steatohepatitis), but in 2023, experts renamed it to better reflect its link to metabolic problems like obesity, type 2 diabetes, high blood pressure, and high cholesterol. The name change also helped distinguish it from alcohol-related liver disease.

In MASH, the liver’s fat levels rise beyond normal, leading to liver fat accumulation. When liver cells are under stress from this fat, metabolic hepatic inflammation and occasionally irreversible hepatocellular damage result. Over time, this can advance to MASH liver fibrosis or MASH cirrhosis, and in severe cases, liver failure or cancer.

What makes MASH liver disease especially concerning is that it can develop silently, without symptoms, and may be missed until significant damage occurs. This is why awareness, early detection, and timely MASH treatment are critical.

What are MASH symptoms?

Usually, MASH hides early on, people feel nothing. But when it gets worse:

• You may feel tired or achy in your upper right belly.
• You might notice swelling in your belly or legs.
• Your skin or eyes could turn yellow (jaundice).
• You might lose weight without trying or feel weak.

What causes metabolic dysfunction-associated steatohepatitis?

MASH often appears when the body doesn’t process fat or sugar well. Common causes include:

• Being overweight or obese.
• Type 2 diabetes.
• High cholesterol or blood fat (high triglycerides).
• High blood pressure.
• Insulin resistance (when the body ignores insulin signals).

These conditions make the liver work too hard, leading to liver fat accumulation, metabolic liver inflammation, and hepatocellular damage.

What are the complications of MASH?

Left unchecked, MASH can worsen and lead to:

• Liver fibrosis: scarring in the liver.
• Cirrhosis: heavy scarring that damages liver function.
• Liver failure or liver cancer (hepatocellular carcinoma).

MASH also raises risks for heart disease, kidney disease, and even other cancers.

Shockingly, many people, maybe 20 million in the U.S., UK, Germany, and France have MASH but don’t know it.

How do healthcare providers diagnose MASH?

Because MASH symptoms are often absent in the early stages, diagnosis relies on targeted evaluation rather than waiting for signs to appear.

Blood tests

Doctors first check liver function through enzymes like ALT and AST. Elevated levels can suggest fatty liver inflammation or injury. To identify associated metabolic issues, further tests may be performed to measure fasting glucose, HbA1c, and cholesterol. While blood tests can hint at MASH diagnosis, they can’t confirm it alone.

Imaging tests

Ultrasound is often the first imaging choice because it’s quick, safe, and detects fat in the liver. More advanced imaging, such as FibroScan or MRI-PDFF, can measure fat content and assess stiffness; an indicator of scarring in Chronic liver disease MASH. These tools help detect liver fat accumulation and early MASH liver fibrosis without invasive procedures.

Liver biopsy

If results remain uncertain or advanced disease is suspected, a liver biopsy is the gold standard. A small sample of tissue is analyzed for fat content, inflammation, and scarring. This step can confirm Steatohepatitis due to metabolic dysfunction and help guide treatment.

How is MASH treated?

There’s no one-size-fits-all approach to MASH treatment. Management focuses on slowing or reversing damage while addressing the root causes.

Lifestyle changes

Weight loss is the most effective therapy. Reducing body weight by 5–10% can improve liver inflammation, while 10% or more can resolve MASH in many cases. A balanced diet with fewer refined carbs and more whole foods helps. Regular activity, at least 150 minutes of moderate exercise weekly, supports MASH reversal. Managing blood sugar, cholesterol, and blood pressure also reduces progression risk.

Medication

While no pill can fully cure metabolic dysfunction-associated steatohepatitis, certain medications help. Rezdiffra (resmetirom) is the first FDA-approved drug for MASH, shown to reduce fat and scarring. Diabetes and weight-loss drugs like GLP-1 receptor agonists (e.g., semaglutide) can also improve liver health. Vitamin E and pioglitazone may be used in select patients under close supervision.

Bariatric surgery

For individuals with obesity-related liver disease who cannot achieve enough weight loss through diet and exercise, bariatric surgery can significantly reduce liver fat accumulation and improve scarring. In some cases, it halts progression to MASH cirrhosis.

Is MASH curable?

There’s no simple cure. But, with weight loss, healthy habits, and sometimes medications or surgery, MASH can improve or stop progressing. Fortunately, many individuals report noticeable improvements.

What’s the life expectancy for someone with MASH?

Life expectancy with MASH depends on how early it’s detected and managed. Without treatment, scarring from NASH can progress by one stage every 6–7 years. Advanced stages, like MASH cirrhosis, carry higher risks of liver failure, liver cancer, and death.

Research shows people with metabolic dysfunction-associated steatohepatitis have a higher mortality rate than those with MASLD. The most common causes of death are liver disease complications, cardiovascular events, and certain cancers.

With early detection, healthy lifestyle changes, and the right MASH treatment, many patients can stabilize or even improve their liver health, dramatically boosting their life expectancy.

When should I see my healthcare provider?

See your doctor if:

• You have obesity, diabetes, high blood pressure, or high cholesterol.
• You feel tired, or have belly discomfort.
• Your liver blood tests aren’t normal.
• You’re overweight or pre-diabetic and worried about liver health.

Conclusion

Metabolic dysfunction-associated steatohepatitis is not a rare condition; it’s a growing global health problem hidden within the spectrum of nonalcoholic fatty liver disease. It develops quietly, often without warning, but can cause severe liver damage over time.

The good news is it’s not hopeless. With early MASH diagnosis, lifestyle adjustments, and modern treatment options, it’s possible to slow, stop, or even reverse the damage. The key is awareness: know your risks, get checked if you have diabetes, obesity, or high cholesterol, and take steps now to protect your liver. It’s critical to your liver and future health.