A liver disease once widely discussed as fatty liver is now drawing broader national attention as obesity, diabetes, and metabolic risk factors remain common in the United States. The condition at the center of that attention is metabolic dysfunction-associated steatotic liver disease, or MASLD, a largely symptom-free illness in its early stages that can progress to scarring, liver failure, or cancer. Its rising profile sharpened on March 14, 2024, when the U.S. Food and Drug Administration approved the first drug specifically for adults with more advanced inflammatory disease known as MASH.
The disease now affecting millions
MASLD is the updated name for what many patients and doctors previously called nonalcoholic fatty liver disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases and the American Association for the Study of Liver Diseases. Federal health materials describe it as a buildup of fat in the liver linked to metabolic dysfunction rather than heavy alcohol use. Because many people have no clear symptoms at first, it is often described by clinicians as a silent disease.
The “1 in 3 Americans” framing reflects the broad burden of disease in adults. NIDDK describes fatty liver disease as one of the most common and growing chronic liver diseases, while American Liver Foundation materials say about one in three U.S. adults are believed to have MASLD and about 20% of those patients may have the more serious inflammatory form, MASH. FDA materials issued with the first MASH drug approval stated that about 6% of U.S. adults, or roughly 14.9 million people, have MASH.
That March 14, 2024 approval covered Rezdiffra, the brand name for resmetirom, for adults with noncirrhotic MASH and moderate to advanced liver scarring, the FDA announced. The agency said the drug was approved for use alongside diet and exercise, marking the first federal approval of a treatment aimed directly at this stage of the disease. The action did not apply to all people with MASLD, but it signaled a shift from awareness alone to active treatment for a defined high-risk group.
What the U.S. impact looks like
The scope of MASLD is national, but the burden is closely tied to other common chronic conditions seen in every state. CDC data show obesity remains widespread among U.S. adults, and federal diabetes data show diagnosed and undiagnosed diabetes are far more common among adults with overweight or obesity than among adults at lower weight ranges. Those patterns matter because diabetes, obesity, abnormal cholesterol, and related metabolic conditions are among the main risk factors tied to MASLD and MASH.
What is confirmed is that millions of Americans likely have liver fat disease and many do not know it. What is not yet known is exactly how many people in each state have been diagnosed, because broad prevalence estimates and confirmed case counts are not the same thing. There is also no single national patient registry that publicly lists state-by-state MASLD totals in real time.
Screening is becoming more structured in primary care and diabetes care. AASLD guidance identifies the FIB-4 blood-test calculation as a useful first step to help identify patients at higher likelihood of advanced fibrosis, and the American Diabetes Association’s 2026 standards say FIB-4 is the most cost-effective initial screening strategy for at-risk MASH in primary care and diabetes settings. That means more patients may be flagged for follow-up imaging or specialist referral even if they feel well.
Why the disease is getting more attention now
The main reason MASLD is gaining visibility is the overlap with the nation’s broader metabolic health trends. According to CDC obesity data and federal diabetes statistics, large numbers of adults are living with conditions that raise MASLD risk. Liver specialists have also emphasized that the disease can advance quietly for years, which has contributed to underdiagnosis until scarring or abnormal lab work appears.
Another reason is that medical guidance and terminology have changed. AASLD and related liver experts have adopted MASLD and MASH terminology in place of older NAFLD and NASH labels, and the updated language is increasingly appearing in clinical guidance, hospital materials, and public education. That shift is intended to align the disease name more closely with its metabolic drivers and standardize screening discussions across specialties.
For patients, the practical takeaway is narrower than the headline but still significant. The FDA-approved treatment is for adults with noncirrhotic MASH and moderate to advanced fibrosis, not for every person with liver fat, and diagnosis still depends on clinical evaluation, blood work, and often noninvasive testing, according to the FDA and AASLD guidance. Even so, the combination of broader screening recommendations, updated disease names, and the first approved therapy means this once-overlooked condition is likely to remain a larger part of routine U.S. medical care.