If you've recently been told you have fatty liver — often as an incidental finding on an ultrasound done for something else — the first thing to know is this isn't a single condition. It's a spectrum. Where you are on that spectrum determines how reversible it is and what you need to do about it. In this post we'll break down the four stages of non-alcoholic fatty liver disease (NAFLD), what blood work and imaging look like at each stage, and the single most important driver to manage if you want this to reverse.
NAFLD — non-alcoholic fatty liver disease — is a broad term covering a range of conditions characterized by accumulation of fat in the liver cells (hepatocytes). The "non-alcoholic" part is key: while some people with NAFLD also drink, this condition develops from non-alcohol-related causes. It's tightly tied to metabolic risk factors — obesity, insulin resistance, metabolic syndrome, diabetes. Even just having increased abdominal girth raises your risk.
This is very common in the modern population. Not normal — but common. Most people find out about it after an unrelated abdominal ultrasound shows fatty liver as an incidental finding. If that happened to you, the first step isn't panic; it's figuring out which stage you're in.
Steatosis is the earliest and mildest form. Excess fat is accumulating in liver cells without significant inflammation or cell damage. There may be some early damage starting, but it's not pronounced.
The good news: steatosis is generally considered reversible. It doesn't progress in everyone, especially if you address the underlying drivers. The mechanism is mostly about insulin resistance and triglyceride handling. Carbs get stored as glycogen first; once glycogen stores are full, the body converts the excess into triglycerides. Some triglyceride gets exported and stored in fat tissue, but if there's still too much for the body to handle, some of it gets stored as fat right in the liver. That's what shows up on the ultrasound.
The intervention at this stage is straightforward: keep your insulin resistance numbers in check, watch your triglycerides, and the fat accumulation comes down.
NASH is more advanced. It's still fat in the liver — but now there's also inflammation and actual liver cell damage. Steato (fat) + hepa (liver) + itis (inflammation). The inflammation pattern resembles alcohol-related liver damage, which is why I've seen so many patients told for years to stop drinking even though they don't drink at all. The labs look the same. The driver is different.
What's happening: those excess triglycerides are now damaging liver cells. When cells die, their contents — including liver enzymes — leak into the bloodstream. That's the elevated liver enzymes (ALT, GGT, AST) you see on labs.
Important: elevated liver enzymes alone don't equal NASH — there are many other causes. But elevated liver enzymes plus imaging showing fatty liver does strongly suggest NASH. This stage is still reversible, but the window is narrower than at stage 1, and the seriousness of the situation is real. If you're seeing rising ALT or GGT alongside a fatty liver finding, that's the moment to get serious about insulin resistance.
Fibrosis is scar tissue forming in response to ongoing damage. The cells keep getting damaged, the body can't keep up with repair, so it lays down scar tissue instead. Once scar tissue forms, it's much harder to reverse — and beyond a certain point, it doesn't reverse at all. The liver is a remarkably regenerative organ, but only up to a point. Once fibrosis is extensive, the liver can't keep up with the body's demands.
Fibrosis usually develops after years of NAFLD with elevated liver enzymes. It's checked with a special type of liver ultrasound (fibroscan / transient elastography) which can stage how much fibrotic tissue is present. Liver biopsy is another option, but it's rarely done these days because the imaging is good enough.
Cirrhosis is the most advanced stage — permanent scarring across enough of the liver that function is meaningfully compromised. At this stage you may still see elevated liver enzymes, or sometimes you don't (the liver isn't producing as much). What you'll start to see instead are downstream signs: lower platelet counts, decreased clotting factors, decreased blood proteins (because the liver makes those). Portal hypertension can develop, which can cause swelling in the abdomen and legs.
This is the stage where reversal isn't on the table — the goal becomes preventing further decline.
The most important target is keeping your insulin resistance markers under control — and doing it consistently for long stretches, not in short bursts. Triglycerides, fasting glucose, A1c, fasting insulin all matter. The tighter you keep these, the less fat ends up in the liver and the less damage occurs.
Concretely: I want liver enzymes under 25. The standard "normal" range goes much higher than that — but at 25 or below you have meaningful margin from active inflammation. And even when one test looks fine, the underlying insulin resistance markers still need to be normal.
Pay particular attention to fructose. Fructose is processed in the liver and can be especially damaging to liver cells. That means high-fructose corn syrup, sweetened drinks, and even some high-fructose fruits add up. This isn't an "all sugar is bad" message — it's a "fructose specifically punches above its weight on liver damage" message.
It's also worth checking iron. Inflammation in the liver can drive iron accumulation, showing up as elevated ferritin. Elevated iron can in turn worsen liver damage — so the two often feed each other.
Fatty liver isn't a single thing. Steatosis is reversible. NASH is reversible if you act. Fibrosis becomes increasingly hard to reverse. Cirrhosis is permanent. The earlier in the spectrum you catch this, the more leverage you have. Get the imaging, get the liver enzymes, and look hard at insulin resistance. The labs that don't seem related — fasting insulin, triglycerides, A1c — are the ones that drive what's happening in the liver.
If you're seeing elevated liver enzymes alongside fatty liver, glutathione is one of the supplements I most often recommend to support liver detoxification. Here's the one I use with patients. Or work with me directly to build a treatment plan around your specific labs.
Topics: Fatty Liver, NAFLD, NASH, Cirrhosis, Insulin Resistance, Liver Enzymes, Triglycerides, Fibrosis