How Doctors Now Diagnose MASH: A Two-Step Liver Screening Breakthrough

Metabolic dysfunction-associated steatohepatitis (MASH) is now one of the most widespread liver diseases in the U.S., alongside alcohol-related liver disease and metabolic dysfunction-associated steatotic liver disease (MASLD). Doctors are increasingly screening for the condition, particularly in patients with risk factors like obesity, Type 2 diabetes, or a family history of liver disease. A structured two-step approach helps confirm a diagnosis and assess the severity of liver damage.

The first step in diagnosing MASH involves a simple blood test. Using routine results—platelet count, ALT, AST levels, and age—doctors calculate the fibrosis-4 index (FIB-4). If the score reaches 1.3 or higher, it signals an intermediate to high risk of liver fibrosis.

A score at this level triggers further testing. Patients then undergo vibration-controlled transient elastography, commonly known as FibroScan®. This non-invasive procedure measures liver stiffness, indicating the degree of scarring (fibrosis), which can range from mild (F0) to advanced (F4). Advanced scarring, or F4, is equivalent to cirrhosis. In some cases, additional tests are needed for a clearer picture. These may include magnetic resonance elastography and proton density fat fraction (MRE-PDFF) or, in more complex situations, a liver biopsy. Such steps help determine the exact level of scarring and guide treatment decisions. Healthcare providers, including primary care doctors, endocrinologists, and obesity specialists, are now actively screening high-risk patients. Early detection remains key, as MASH can progress silently before causing serious harm.

The two-step diagnostic process—starting with FIB-4 and followed by FibroScan®—helps identify liver fibrosis in MASH patients. Additional imaging or biopsy may be required for a precise assessment. With proactive screening, doctors aim to catch the disease early and prevent severe liver damage.