You probably know someone who feels tired for weeks and shrugs it off. Most of us have wondered at some point whether an ache under the ribs means something real. Sometimes it does, and the clue sits in an organ that rarely speaks up.
About 24% of US adults have nonalcoholic fatty liver disease, now also called MASLD, according to the National Institute of Diabetes and Digestive and Kidney Diseases. It is the most common chronic liver condition in the country, and most people with it have no idea.
Doctors call it silent because it rarely sends a clear signal in its early stage. By the time symptoms become obvious, scarring is often already advanced.
Why the early stage can feel like nothing at all
In its mildest form, fat simply builds up in the liver and does not cause damage. The NIDDK describes this stage as having few or no symptoms at all.
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When early symptoms do show up, they are vague. The NIDDK lists two that tend to come first, feeling tired and discomfort in the upper right side of the abdomen, where the liver sits under the ribs.
That mild ache rarely sends anyone to the doctor. Many people only find out they have the condition when a routine blood test picks up elevated liver enzymes.
The signs that mean the liver is already struggling
When fat triggers inflammation and scarring, a more serious form called MASH can develop. It used to be known as NASH. The Cleveland Clinic lists a cluster of specific signs for this stage.
These include extreme fatigue and weakness, an ache in the upper right abdomen, loss of appetite, a swollen belly, unexpected weight loss, and yellowing of the skin or eyes.
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That last sign, called jaundice, points to serious liver damage. It is a reason to see a doctor without delay.
Who carries the risk without knowing
Fatty liver disease tracks closely with how the body handles sugar and fat. The NIDDK says it is present in up to 75% of people who are overweight, and in more than 90% of people with severe obesity.
Among people with type 2 diabetes, one third to two thirds have it. Other risk factors include insulin resistance, where cells respond less well to the hormone insulin, high triglycerides, abnormal cholesterol, and metabolic syndrome.
If you fall into any of these groups, ask your doctor about a simple liver enzyme panel. It measures two markers called ALT and AST, and raised levels can prompt an ultrasound or a scan called elastography to check for scarring.
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What actually shrinks liver fat
Weight loss is still the first step. The NIDDK notes that losing 3% to 5% of body weight can reduce liver fat, and losing 7% to 10% can also reduce inflammation and scarring.
For the first time, there are also approved drugs. The FDA approved resmetirom, sold as Rezdiffra, in March 2024 for adults with MASH and moderate to advanced scarring, as long as they do not already have cirrhosis.
In August 2025, the FDA added semaglutide, the active ingredient in Novo Nordisk's Wegovy, for the same group. The approval, reported by HCPLive, excludes patients whose disease has progressed to cirrhosis.
Both drugs are meant to be used alongside diet and exercise, not instead of them. If you have a known risk factor, ask your primary care doctor for a liver enzyme panel at your next visit.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.