Transaminitis is a term for higher-than-normal levels of liver enzymes in your blood, specifically alanine transaminase (ALT) and aspartate transaminase (AST). It’s not a disease itself but a lab finding, one that signals your liver cells are injured or inflamed enough to leak these enzymes into your bloodstream. Mild elevations are extremely common and often show up on routine blood work with no symptoms at all.
How Liver Enzymes End Up in Your Blood
ALT and AST are enzymes that normally live inside liver cells, where they help process amino acids. When something damages those cells, the cell membranes become leaky or break down entirely, releasing ALT and AST into the bloodstream. A standard blood panel picks up these elevated levels, and that’s what gets flagged as transaminitis.
ALT is found almost exclusively in the liver, which makes it a more specific marker of liver injury. AST also exists in the heart, muscles, kidneys, and brain, so an elevated AST on its own can sometimes reflect damage outside the liver. When both enzymes are elevated together, the liver is the most likely source.
Normal Ranges and Severity Levels
Reference ranges vary slightly between labs, but a large 2024 study in Liver International established updated limits for healthy adults free of liver-affecting medications. For ALT, the upper limit was about 57 U/L for men and 35 U/L for women. For AST, it was roughly 49 U/L for men and 33 U/L for women. Numbers above these thresholds are considered elevated.
Clinicians typically classify the degree of elevation based on how many times it exceeds the upper limit of normal (ULN):
- Mild: Less than 5 times the ULN. This is the most common finding in primary care and rarely signals an emergency.
- Moderate to severe: 5 times the ULN or higher. This prompts more immediate evaluation because it can indicate acute liver injury from a virus, a drug reaction, or another serious cause.
A mildly elevated result on a single blood draw doesn’t necessarily mean something is wrong long-term. Temporary spikes can happen after intense exercise, a night of heavy drinking, or even from certain supplements. Persistent elevation over weeks or months is what raises clinical concern.
The Most Common Causes
Non-alcoholic fatty liver disease (NAFLD) is now the leading cause of abnormal liver enzymes worldwide, driven largely by rising rates of obesity. An estimated 20% of the general population has some degree of NAFLD, and that number climbs to around 70% among people with type 2 diabetes. In most cases, the fat accumulation causes mild, chronic enzyme elevation without progressing to serious liver damage. But in about 3% to 5% of the general population, the condition advances to a more inflammatory stage called non-alcoholic steatohepatitis (NASH), which can lead to scarring over time.
Alcohol-related liver disease is the other major cause. A useful diagnostic clue is the ratio between AST and ALT. In alcohol-related liver injury, about 90% of patients have an AST level more than double their ALT level. This pattern occurs because alcohol depletes a vitamin (B6) that the liver needs to produce ALT, while simultaneously damaging structures inside liver cells that release extra AST. An AST-to-ALT ratio greater than 2:1 strongly suggests alcohol as the underlying driver, though advanced scarring from any cause can also shift the ratio.
Medications are another frequent culprit. Acetaminophen (Tylenol) is the most common drug to cause dose-dependent liver injury, but the list extends well beyond pain relievers. Cholesterol-lowering statins, certain antibiotics, anti-seizure medications, and even over-the-counter anti-inflammatory drugs can trigger enzyme elevations. Herbal supplements are an often-overlooked source. Products containing ingredients like ephedra, germander, chaparral, and senna have all been linked to liver enzyme spikes. Many people don’t think to mention supplements when discussing medications, but they can be significant.
Less common causes include viral hepatitis (especially hepatitis B and C), autoimmune hepatitis, thyroid disorders, and celiac disease. Intense physical activity, particularly endurance exercise or heavy weightlifting, can also temporarily raise AST because of muscle breakdown rather than liver damage.
Why You Might Not Have Any Symptoms
Most people discover transaminitis through a routine blood test, not because they feel sick. The liver has enormous functional reserve, meaning it can sustain significant injury before you notice anything. Mild to moderate elevations often produce no symptoms whatsoever.
When symptoms do appear, they tend to reflect the underlying cause rather than the enzyme elevation itself. Fatigue is the most common complaint, though it’s vague enough that many people attribute it to stress or poor sleep. More specific signs of liver trouble, like yellowing of the skin or eyes (jaundice), dark urine, pale stools, or pain in the upper right abdomen, usually only develop once liver damage is more advanced or when the elevation is acute and severe.
How Transaminitis Is Evaluated
A single elevated reading typically leads to a repeat blood test in a few weeks to see if the numbers normalize on their own. If the elevation persists, the next step is usually a broader liver panel and targeted blood tests. These might include screening for hepatitis B and C, checking iron and copper levels, testing for autoimmune markers, and evaluating thyroid function.
Your provider will also review every medication you take, including over-the-counter drugs, supplements, and herbal products. This medication review is one of the most important parts of the evaluation because drug-related liver injury is common and usually reversible once the offending product is stopped. About 90% of people with drug-induced liver injury recover after discontinuing the responsible medication.
An abdominal ultrasound is often ordered to check for fatty liver, gallstones, or structural abnormalities. If the cause remains unclear after blood work and imaging, or if the enzyme levels are rising, a liver biopsy or specialized imaging may follow.
Treatment Depends Entirely on the Cause
There’s no single treatment for transaminitis because it’s a symptom, not a diagnosis. Management targets whatever is driving the enzyme elevation.
For NAFLD, the primary approach is gradual, sustained weight loss through reduced calorie intake and increased physical activity. Even a 5% to 10% reduction in body weight can meaningfully lower liver enzyme levels and reduce fat in the liver. No medication is specifically approved for NAFLD in most cases, making lifestyle changes the frontline strategy.
For alcohol-related liver disease, the goal is stopping harmful drinking, which for most people means complete abstinence. Enzyme levels often begin to drop within weeks of quitting, and the liver has a remarkable ability to repair itself if scarring hasn’t become too extensive.
When a medication is the cause, discontinuing or switching the drug is usually all that’s needed. Your provider will weigh the benefit of the medication against the severity of the liver enzyme elevation. Mild statin-related elevations, for instance, don’t always require stopping the drug, while a progressive rise would.
For viral hepatitis, autoimmune conditions, or rarer causes, treatment is specific to that disease and typically involves specialist care from a hepatologist or gastroenterologist.
What Persistent Elevation Means Long-Term
Chronically elevated liver enzymes that go unaddressed can reflect ongoing liver inflammation, which over years or decades may progress to fibrosis (scarring) and eventually cirrhosis. This progression isn’t inevitable, particularly if the cause is identified and managed early. Most people with mild transaminitis never develop serious liver disease.
The enzymes themselves don’t cause harm. They’re messengers. Paying attention to what they’re telling you, and addressing the root cause, is what determines your long-term liver health.