Call 911 or go to an emergency department now if you are confused or unusually drowsy, if you are vomiting blood or passing black tarry stools, if you have severe abdominal pain, or if you cannot keep any fluids down.
Most of the time, tiredness, nausea, aching joints and a flat appetite come from ordinary life rather than from a virus. The everyday causes are far more common than any lab finding, and several of them often stack up in the same week.
A smaller group of symptoms points more specifically toward the liver. Yellowing of the whites of the eyes or the skin, urine that turns the colour of strong tea, stools that look pale or clay coloured, and a dull ache under the right ribs belong in that group. None of them confirms a cause by itself, but together they are a reason to be seen rather than to wait.
Hepatitis B is an infection of the liver caused by the hepatitis B virus. Research suggests that the course of infection depends heavily on the age at which it is acquired, with infection acquired in adult life far more often clearing on its own than infection acquired early in life 1. The symptoms are not limited to the liver either. Studies indicate that hepatitis B can involve other systems, with joint, skin and kidney features described as extra-hepatic manifestations 2.
Acute infection is the first stretch after exposure, and long-term infection is what clinicians call it when the virus is still detectable beyond six months. The two feel very different from the inside, and often neither one feels like much at all.
In the acute phase, some people get a flu-like illness with fatigue, low appetite, nausea, mild fever and aching joints, which may or may not be followed by jaundice. Many people get nothing noticeable. Research suggests that a large share of acute infections in adults pass without the person ever recognising a distinct illness, and that most adults go on to clear the virus 1.
Long-term infection is usually quiet. Instead of steady symptoms, what changes over time is what the blood shows. Management guidelines describe distinct phases of chronic hepatitis B defined by viral markers and ALT rather than by how the person feels, which is why periodic blood tests carry more weight than a symptom diary 3. Guidelines also set out how often those markers are rechecked in people with chronic infection, because the picture shifts over years rather than weeks 4.
That quietness is the practical problem. A person can feel entirely well for a long time while the liver is still being affected, so symptoms alone are a poor way to judge what is happening.
Hepatitis B spreads when blood or certain body fluids from a person carrying the virus get into another person's body. It is a bloodborne virus, not an airborne one, and that single fact explains most of the routes.
The recognised routes include sharing injecting equipment, needlestick injuries in healthcare and other settings, tattooing or piercing with equipment that has not been properly sterilised, medical or dental procedures using unsterile instruments, and sex without barrier protection. Sharing personal items that can carry traces of blood, such as razors or toothbrushes, is also a route. Equipment that has not been sterilised is the common thread in several of these.
Just as useful is what does not spread it. Hugging, holding hands, kissing on the cheek, coughing, sneezing, sharing food, plates or cutlery, and ordinary household or workplace contact do not pass the virus. Hepatitis B is common worldwide, and acquiring it says nothing about a person's character, cleanliness or choices.
The virus itself is not uniform. It exists as several genotypes that differ in how they are distributed around the world, and research suggests that this genetic diversity has clinical implications for how infection behaves and how it is followed 5.
Two routine liver enzymes, ALT and AST, are the markers most often checked when symptoms like these are assessed. They do not identify hepatitis B. What they do is show whether liver cells are being irritated, which helps a clinician decide what to look for next.
| Marker | Why it is linked to this symptom | What a result can and cannot tell you |
|---|---|---|
| ALT | Sits mostly inside liver cells and leaks into the blood when those cells are injured, so it is the enzyme most closely tied to liver irritation behind fatigue, nausea and right-sided discomfort | Can show that liver cells are under strain and give a rough sense of how much. Cannot say why, and cannot rule hepatitis B in or out, because it can be normal during long stretches of infection |
| AST | Rises with liver cell injury as well, which is why it is run alongside ALT when jaundice, dark urine or upper abdominal pain are being assessed | Adds context to an ALT result and helps a clinician judge the pattern. Cannot localise the source, because it also comes from heart muscle, skeletal muscle and red blood cells |
| Marker | Typical adult lab reference range | Unit |
|---|---|---|
| ALT | roughly 7 to 56 | U/L |
| AST | roughly 10 to 40 | U/L |
These are typical lab reference ranges, and they vary by lab, age and sex. The range printed on your own report is the one your result should be read against.
Confirming or excluding hepatitis B needs specific hepatitis B blood tests, not liver enzymes. Diagnosis rests on serological markers of the virus and the body's response to it, and guidelines set out which ones are used and how they are interpreted together 6. A clinician orders and reads those.
Not on its own, but a raised ALT is one of the first things a clinician checks when liver irritation is a possible reason for how you feel. ALT, or alanine aminotransferase, is an enzyme concentrated inside liver cells. When those cells are inflamed or injured, some of the enzyme escapes into the bloodstream and the measured level climbs.
In long-term hepatitis B the number does not sit still. Guidelines describe periods in which ALT stays within range for long stretches and other periods in which it rises sharply, and studies indicate that these swings are part of how the infection behaves over years 7.
Plenty of things other than a virus move ALT. Extra fat carried around the liver, alcohol, an unusually hard or unaccustomed training session, muscle injury, other infections, and some medicines; ask your prescriber. Even the timing of your blood draw relative to a heavy weekend can shift the number.
The reverse matters just as much. ALT can read within range while hepatitis B is present, because normal enzymes are a documented feature of certain phases of chronic infection 3. A single in-range ALT is reassuring about liver cell injury on that day. It is not a clean bill of health, and it is not a hepatitis B test.
AST adds context to ALT, but it is less specific to the liver, so it is rarely read alone. AST, or aspartate aminotransferase, is found in liver cells and also in heart muscle, skeletal muscle and red blood cells. A rise can therefore come from somewhere other than the liver entirely.
That is not a flaw, it is the reason the two are run together. The relationship between AST and ALT, and the direction each moves over repeated tests, is part of what a clinician weighs when assessing someone with chronic hepatitis B, and guidelines fold both into routine monitoring alongside viral markers.
Things that move AST without any liver problem include a heavy leg session two days before the draw, a long run, a recent muscle strain or bruise, breakdown of red blood cells in the sample or in the body, and some medicines; ask your prescriber. Alcohol affects it as well. This is why repeating bloods after a quiet week, with no unusual training and no alcohol, often changes the interpretation more than any extra test would.
As with ALT, a result inside the typical range does not exclude hepatitis B. It tells you that, on the day of the draw, there was no strong signal of ongoing cell injury from the tissues AST comes from.
A completely normal liver panel can sit alongside an active hepatitis B infection, and that is the single most important limit to understand here. Liver enzymes measure the consequence of cell injury, not the presence of a virus.
Specific hepatitis B serology is what detects the virus and the immune response to it, and guidelines describe the combination of markers used to establish the picture 6. Even within that testing there are edge cases. Statements on occult hepatitis B describe people in whom the surface antigen is not detectable while viral DNA can still be found, which is why interpretation belongs with a clinician who can choose the right test for the situation 8.
Symptoms can also sit outside the liver altogether. Research suggests that hepatitis B can present with joint, skin, vascular and kidney features, so a person's main complaint may not look like a liver complaint at all 2.
And then there is everything no blood test shows. Sleep quality, chronic stress, grief, under-eating, low daily movement, ongoing pain and low mood all produce the same fatigue and poor appetite that bring people to a liver panel in the first place. A normal panel does not mean nothing is wrong. It means the explanation is more likely to be found in those areas, or in tests that were not run.
Seek care promptly if the whites of your eyes or your skin look yellow, if your urine turns dark, if your stools turn pale, or if you have persistent pain under the right ribs. Add to that list persistent vomiting, a fever that will not settle, easy bruising or bleeding, and swelling of the abdomen or the legs. These are reasons to be assessed within days rather than at some point.
Some signs need emergency care rather than an appointment. Confusion, unusual drowsiness, vomiting blood, black tarry stools, fainting, severe abdominal pain, or being unable to keep fluids down all mean calling 911 or going to an emergency department now.
There is also a reason to be seen that has nothing to do with symptoms. A needlestick injury, shared injecting equipment, tattooing or piercing with equipment you are unsure about, or sexual contact with a person who has hepatitis B are all worth raising with a clinician quickly, because early infection is usually silent.
Do not diagnose yourself from a symptom list or from one number on a report. A liver enzyme outside the typical range is suboptimal rather than a verdict, and it is worth discussing with a clinician promptly so the right follow-up can be chosen.
If you are having thoughts of self-harm, call or text 988 (US) or your local emergency number now.
The FitScript Essential panel measures both ALT and AST as part of routine bloodwork, which gives you a baseline for liver cell injury rather than a one-off snapshot taken during a bad week. Results are explained in plain language by Atlas, FitScript's AI health advisor, so you can see what each marker tracks, what moved it and what a repeat test would clarify. The membership covers 150+ biomarkers tested per year.
What a liver panel cannot do is confirm hepatitis B. That takes specific hepatitis B blood tests, which a clinician orders and interprets in the context of your history and any exposure. Treatment decisions belong to a licensed provider, who evaluates whether anything is appropriate for the individual in front of them.
This article is educational and not medical advice. Discuss your results, and any next step, with a clinician or licensed provider.
If you are comparing the viral liver infections, the overlap in how they show up is worth reading about in the guide to hepatitis c symptoms, which covers a different virus with a similarly quiet early course.
Many people have none at all. When symptoms do appear, the usual ones are tiredness, poor appetite, nausea, aching joints, mild fever and discomfort under the right ribs. Some people also notice dark urine, pale stools and yellowing of the eyes or skin. These signs are worth checking with a clinician rather than self-assessing.
Long-term infection is often quiet, and many people feel normal for years. When symptoms do surface, they tend to be vague tiredness, low appetite, joint aches or discomfort on the right side of the abdomen. Because the signs are so mild, periodic blood tests and clinician review matter far more than tracking symptoms alone.
Hepatitis B passes when blood or certain body fluids enter another person's body. The usual routes are shared injecting equipment, needlestick injuries, tattooing or piercing with equipment that was not sterilised, medical or dental procedures using unsterile instruments, and sex without barrier protection. Sharing razors or toothbrushes that can carry traces of blood is also a route.
It is not spread by hugging, kissing on the cheek, holding hands, coughing, sneezing, or sharing food, plates and cutlery. Ordinary household and workplace contact does not pass the virus. The routes that matter all involve blood or certain body fluids reaching another person's bloodstream or mucous membranes.
Symptoms, when they happen at all, generally begin weeks to months after exposure rather than within days. The gap varies widely between people, and many never notice an obvious illness at any point. If you know about a specific exposure, ask a clinician about testing instead of waiting to feel unwell.
No. Many adults clear the infection themselves within months, while in others the virus stays long term and is followed with regular blood tests. Which path applies is worked out from blood tests over time, not from how you feel. A licensed provider decides whether any further step is appropriate.
No. ALT and AST show whether liver cells are being irritated, not what is irritating them. They can be raised by alcohol, extra fat around the liver, hard training or other infections, and they can sit in range while hepatitis B is present. Specific hepatitis B blood tests are what confirm it.
Contact a clinician promptly and describe what happened and when. They decide which blood tests to order, how soon to run them, and whether anything else is appropriate for your situation. Avoid donating blood until you have been assessed. Do not rely on a symptom check, because early infection is usually silent.