Yellow skin or eyes together with confusion, drowsiness or vomiting that will not stop needs emergency care now. Call 911 or your local emergency number.
Most of the time, a few days of tiredness, queasiness and a poor appetite come from ordinary life rather than a liver infection. Several everyday causes often stack up at once. The most common are short sleep, a stressful stretch at work, a sharp jump in training load, several heavy nights of drinking, an unfamiliar run of rich food, a passing stomach bug and the shifts that come with a new life stage. Some medicines can also unsettle digestion or nudge liver markers, so ask your prescriber about anything you are taking rather than guessing.
Hepatitis A sits in a different category because it has a clear route in. It is a virus spread by the fecal-oral route, usually through food or water contaminated with traces of stool, or through close contact with someone who is already infected 1. Shellfish harvested from contaminated water, produce handled without careful handwashing and spread inside a household are the settings most often described 2.
Timing is what makes the early picture confusing. After exposure there is a quiet stretch of roughly two to six weeks before anything is felt 2. By then the meal or the trip that mattered has been forgotten, so the illness feels like it arrived out of nowhere.
The first phase looks like a bad flu with a stomach flavour. Fever, aching, deep tiredness, nausea, loss of appetite, a sudden distaste for fatty food and a dull ache under the right ribs are the usual openers 2. Darker urine, paler stools and yellowing of the eyes and then the skin follow in many adults within about a week 3.
Age changes the picture more than almost anything else. Studies indicate that hepatitis A does not settle into a long-term liver infection and that most people recover fully 4.
A vaccine exists and is the main way the infection is prevented 1. Whether it is appropriate for you is a question for a clinician who knows your history.
Three routine markers do most of the work when these symptoms are evaluated. They are ALT, AST and total bilirubin, and they usually appear together on a standard liver panel. None of them names a virus on its own. What they show is whether liver cells are leaking enzymes into the blood, and whether the liver is clearing bilirubin at a normal rate.
| Marker | Why it is linked to this symptom | What a result can and cannot tell you |
|---|---|---|
| ALT | Sits mostly inside liver cells and spills into the blood when those cells are inflamed or injured, which is the core event behind nausea, right-sided discomfort and jaundice in acute hepatitis. | Can show that liver cells are currently irritated and roughly how much. Cannot name the cause, and cannot confirm or rule out a specific virus. |
| AST | Rises alongside ALT in liver injury, so the balance between the two helps a clinician narrow the field of possible causes. | Can support or soften the picture ALT gives. Cannot stand alone, because muscle, heart and red blood cells also release it. |
| Bilirubin Total | The pigment that turns skin and eyes yellow. It builds up when the liver cannot move it into bile at the normal pace. | Can show that clearance has slowed and explain dark urine and pale stools. Cannot separate a benign inherited pattern from liver inflammation without the rest of the panel. |
Typical lab reference ranges for the same three markers are shown below.
| Marker | Units | Typical reference range |
|---|---|---|
| ALT | U/L | about 7 to 56 |
| AST | U/L | about 10 to 40 |
| Total bilirubin | mg/dL | about 0.1 to 1.2 |
These are typical lab reference ranges. Ranges vary by lab, age and sex, so read your own report against the range printed next to your result.
Read the panel as a pattern rather than as three separate numbers. A useful way to think about any result is in three steps. First, what the value shows. Second, what it may reflect, held loosely. Third, what is worth raising with a clinician.
A high ALT can be one sign that liver cells are leaking their contents into the blood, and it is the most useful single routine marker when a liver cause is being considered. The enzyme lives largely inside liver cells. When those cells are inflamed or injured, it escapes into the bloodstream and the measured level climbs.
In acute hepatitis A the rise tends to be large rather than borderline. Research suggests that aminotransferase levels climb steeply in the days before jaundice appears, peak around the time the eyes start to yellow and then fall back over the following weeks 6. Studies suggest that the injury itself comes largely from the immune response to infected liver cells rather than from the virus destroying those cells directly 5.
ALT also moves for reasons that have nothing to do with a virus. Heavy unaccustomed exercise, alcohol, extra fat stored in the liver, other infections and some medicines can all push it up. That is why one raised value is a question rather than an answer. Ask your prescriber about anything you take before drawing a conclusion from a number.
What a raised ALT can tell you is that something is irritating liver cells now. What it cannot tell you is which thing. You can see what ALT measures and how it is reported, and the sensible next step is to bring a raised value to a clinician who can line it up with your symptoms, your exposures and the rest of the panel.
AST gives a second view of the same injury, and the relationship between the two enzymes often says more than either one alone. AST is present in liver cells, but also in skeletal muscle, heart muscle and red blood cells, which makes it the less liver-specific of the pair.
Plenty of ordinary things move AST. A hard session in the gym, a muscle strain, a recent fall and conditions that break down red blood cells can all lift it. A mildly raised AST next to a completely normal ALT often points away from the liver rather than toward it.
What AST can tell you is whether a raised ALT is part of a broader pattern of cell injury. What it cannot tell you is where the injury sits, because the enzyme has several possible sources. The AST page covers what the marker measures, and a clinician reads it alongside your ALT, your bilirubin and what you have been doing in the week before the draw.
Bilirubin is the yellow pigment left behind when red blood cells are broken down, and skin and eyes turn yellow when the liver cannot clear it fast enough. In normal conditions the liver pulls bilirubin out of the blood, attaches a carrier molecule to it and sends it into bile, which carries it out through the gut.
When liver cells are inflamed, that handover slows. Bilirubin backs up into the blood, some of it spills into urine and darkens it, and less pigment reaches the stool, which turns pale. Jaundice in hepatitis A typically follows the first flu-like phase and fades as the liver recovers 3. Some people instead have a drawn-out, itchy course with prolonged jaundice, or a return of symptoms weeks after feeling better, and both are described as unusual but recognised patterns 1.
Total bilirubin also rises for benign reasons. A common inherited variation in bilirubin handling lifts the number mildly and lifelong without any liver injury, and fasting or a short viral illness can nudge it higher still. That is why bilirubin is read next to ALT and AST rather than on its own.
What bilirubin can tell you is whether clearance has slowed enough to explain dark urine, pale stools or visible yellowing. What it cannot tell you is the reason for the slowdown. The Bilirubin Total page explains the measurement, and a raised bilirubin with visible yellowing is worth discussing with a clinician promptly, particularly when the enzymes are high as well.
A normal liver panel is reassuring, but it does not close the question. Timing is the first gap. Enzymes follow a curve, so a draw taken very early after exposure or weeks after recovery can look ordinary even when the liver has been through something.
The second gap is specificity. A routine panel measures injury, not identity. Confirming hepatitis A rests on a specific antibody test rather than on enzyme levels, and that test is not part of a standard liver panel 7. If exposure is a real possibility, say so to your clinician rather than relying on the enzymes to speak for themselves.
The third gap is everything that never shows on bloodwork at all. Sleep debt, grief, a stressful month, a sudden training block, undereating, a passing gut infection and motion-related nausea leave no fingerprint on ALT, AST or bilirubin. Nausea and upper abdominal discomfort can also come from the stomach, the gallbladder, the inner ear or anxiety, and a liver panel is simply the wrong instrument for several of those.
So a clean panel means these three markers look typical today. It does not mean nothing is happening, and it does not replace an examination.
Some symptoms need care the same day rather than at the next convenient appointment. Call 911 or your local emergency number for yellow skin or eyes alongside confusion, unusual drowsiness or vomiting that will not stop, and for easy bruising or bleeding, severe abdominal pain or a sudden inability to keep any fluids down.
Arrange a prompt appointment, within days rather than weeks, for yellowing of the eyes or skin on its own, for dark urine with pale stools, for a fever that has run for several days with deep fatigue, and for any of these after a known exposure to contaminated food or water or to a household contact who has been unwell.
Severity is not evenly spread. A more severe course is associated with older age and with underlying chronic liver disease 1, and studies describe acute liver failure as a rare outcome of this infection 7. In people with existing liver disease, early contact with a clinician matters more, not less.
Do not try to settle this from a symptom list. A clinician examines you, asks about exposures and orders the right test, and treatment decisions belong to a licensed provider.
If you are having thoughts of self-harm, call or text 988 (US) or your local emergency number now.
ALT, AST and total bilirubin are measured together on the FitScript Essential panel, so a single blood draw covers all three with one set of reference ranges printed beside them. Membership includes 150+ biomarkers tested per year, which means these liver markers can be followed over time rather than read once in isolation.
Atlas, FitScript's AI health advisor, explains what each result means in plain language and places it next to the rest of your panel instead of leaving you with a number and a flag. A licensed clinician decides on any next step, including whether further or more specific testing is appropriate for your situation.
This page is educational and is not medical advice. Discuss your results and any treatment with a clinician or licensed provider.
Related reading covers a virus with a very different long-term course in hepatitis c symptoms.
Hepatitis A is a viral infection of the liver that spreads through food or water contaminated with traces of stool, or through close contact with an infected person. It runs a short course and does not become a long-term liver infection. Most people recover fully, and a clinician confirms it with a specific blood test.
The usual hepatitis A infection symptoms start as fever, aching, deep tiredness, nausea, loss of appetite and a dull ache under the right ribs. Darker urine, paler stools and yellowing of the eyes and skin often follow within about a week. Many children have no symptoms at all.
Hepatitis A virus symptoms arrive in two waves for most adults. First comes a flu-like phase with fever, fatigue, nausea and a distaste for food, then a jaundice phase with yellow eyes or skin, dark urine and pale stools. Symptoms begin weeks after exposure, not immediately.
The illness is short-lived for most people and resolves as the liver recovers, though some have a longer course with prolonged yellowing and itching, or symptoms that return weeks after feeling better. Recovery time varies by person. Ask a clinician what to expect in your own case rather than planning around an average.
A standard liver panel measures ALT, AST and total bilirubin. ALT and AST show whether liver cells are leaking enzymes into the blood, and bilirubin shows whether the liver is clearing pigment at a normal pace. Confirming a specific virus needs an additional antibody test that a clinician orders.
Yes. Many infections, especially in young children, pass with few or no noticeable symptoms, which is part of why the virus can spread within a household before anyone realises. A person can still pass it on during that period. Careful handwashing and food hygiene matter most in that window.
No. Enzyme levels follow a curve, so a draw taken very early or well after recovery can look ordinary. A liver panel also measures injury rather than identity, so it cannot confirm or exclude a specific virus. Tell your clinician about any exposure instead of relying on the numbers alone.
Contact a clinician promptly rather than waiting to see whether it fades. Yellow eyes or skin alongside confusion, drowsiness or vomiting that will not stop is an emergency, so call 911 or your local emergency number. Bring recent bloodwork and a note of any travel, shared meals or unwell household contacts.