Fatty liver disease usually causes no symptoms at all in its early stages. Most people discover they have it through routine blood work or an imaging scan done for another reason. When signs do appear, they tend to be vague: persistent tiredness, a dull discomfort under the right side of your ribs, and a general sense of feeling unwell. The disease affects roughly one in three adults worldwide, and because it’s so quiet early on, knowing what to watch for at every stage matters.
Early Signs Are Easy to Miss
The most common early sign of fatty liver is no sign at all. Fat can accumulate in liver cells for years without producing anything you’d notice. When early symptoms do show up, they’re the kind most people brush off: fatigue that doesn’t improve with rest, mild discomfort or a feeling of fullness in the upper right part of your abdomen (where the liver sits, just below your ribs), and a vague sense of being run down. None of these point clearly to a liver problem, which is why fatty liver is so frequently caught by accident.
Mildly elevated liver enzymes on a standard blood panel are often the first clue. Two enzymes, ALT and AST, reflect liver cell damage. Normal ALT runs between 7 and 55 units per liter, and normal AST between 8 and 48. When either is persistently above those ranges without an obvious explanation like alcohol use or a medication side effect, your doctor will typically investigate further. That said, some people with fatty liver have completely normal enzyme levels, so blood work alone isn’t enough to rule it out.
Signs That the Disease Is Progressing
Simple fat in the liver is the mildest form. The concern is when the liver becomes inflamed, a stage sometimes called NASH (nonalcoholic steatohepatitis). Inflammation can trigger scarring over time, gradually replacing healthy tissue with fibrous tissue. Even at this stage, the disease is often silent. Fatigue can occur at any point, but more noticeable symptoms like unexplained weight loss and muscle weakness tend to appear only once significant scarring has developed.
As scarring worsens, you may notice changes that seem unrelated to your liver. Skin changes are among the more distinctive ones. Spider angiomas, which are small red spots with thin blood vessels radiating outward like spider legs, can appear on the chest, face, and arms. The palms of your hands may develop persistent redness, particularly on the fleshy areas at the base of the thumb and below the pinky finger. These changes happen because a damaged liver can’t properly regulate certain hormones that affect blood vessels.
Late-Stage Warning Signs
When fatty liver progresses all the way to cirrhosis, meaning extensive, permanent scarring, the signs become harder to ignore. At this point, the liver is losing its ability to perform basic functions: filtering toxins, making proteins that help blood clot, and managing fluid balance throughout the body.
The most recognizable late-stage signs include:
- Jaundice: yellowing of the skin and the whites of the eyes, caused by a buildup of a waste product the liver can no longer process efficiently
- Abdominal swelling: fluid accumulates in the belly, sometimes dramatically, because of increased pressure in blood vessels around the liver
- Leg swelling: that same pressure buildup pushes fluid into the lower legs and ankles
- Easy bruising and bleeding: the liver produces clotting proteins, so when it fails, even minor bumps leave large bruises and small cuts bleed longer than expected
- Mental confusion: a damaged liver can’t clear toxins from the blood effectively, and those toxins reach the brain, causing difficulty concentrating, drowsiness, and in severe cases, unresponsiveness
- Gastrointestinal bleeding: blood may appear in vomit or stool, a sign that swollen veins in the digestive tract have ruptured
These symptoms signal advanced cirrhosis and represent a medical emergency when they appear suddenly or worsen quickly.
Signs in Children Look Different
Fatty liver isn’t limited to adults. In children, the disease often presents with even fewer obvious symptoms. A physical exam might reveal obesity concentrated around the waist and an enlarged liver, but the exam can also be completely normal. One subtle clue doctors look for is acanthosis nigricans: patches of dark, velvety skin on the back of the neck and in the armpits. This skin change signals insulin resistance, which is closely tied to fat accumulation in the liver. If your child has this darkening along with excess weight around the midsection, their pediatrician may recommend checking liver enzyme levels.
How Fatty Liver Gets Diagnosed
Because symptoms are unreliable, diagnosis depends on imaging and sometimes blood work. The most common first step is an abdominal ultrasound. Radiologists look for a “bright liver,” meaning the liver appears unusually bright compared to the nearby kidney because fat reflects sound waves differently than normal tissue. Ultrasound can detect fatty liver, but it’s less precise at measuring exactly how much fat is present or how much scarring has occurred.
A more detailed option is a FibroScan, which measures both the amount of fat and the stiffness of the liver (stiffness correlates with scarring). The fat measurement, called a CAP score, ranges from 100 to 400 and is measured in decibels per meter. A score between 238 and 260 suggests roughly 11 to 33 percent of the liver is affected. Scores between 260 and 290 indicate 34 to 66 percent fat involvement, and anything above 290 means two-thirds or more of the liver has fatty changes. These numbers help your doctor determine severity and track whether the condition is improving or worsening over time.
Who Is Most at Risk
Globally, about 32 percent of people have fatty liver disease, and prevalence has been climbing. The rates vary by region: Latin America has the highest at roughly 44 percent, followed by the Middle East and North Africa at about 37 percent. North America sits around 31 percent, and Western Europe is the lowest among studied regions at 25 percent.
The strongest risk factors are carrying excess weight (particularly around the midsection), having type 2 diabetes or insulin resistance, high triglycerides, and high blood pressure. But fatty liver can also develop in people who appear lean, especially those with metabolic issues that aren’t immediately visible. If you have any combination of these risk factors, routine blood work that includes liver enzymes is a reasonable way to catch the disease before symptoms ever appear.