Hepatitis A and hepatitis B are both viral liver infections, but they differ in how they spread, how long they last, and whether they're curable. Hepatitis A spreads mainly through contaminated food or fecal-oral contact and always clears on its own. Hepatitis B is blood-borne and sexually transmitted, and can become a lifelong chronic infection.
Hepatitis A virus
Hepatitis B virus
| Item | Value |
|---|---|
| Hepatitis A | curable — Hepatitis A virus |
| Hepatitis B | managed — Hepatitis B virus |
The bottom-line difference
Hepatitis A is an acute, self-limited illness that your immune system clears completely. Hepatitis B can either resolve in a few months or settle in for life. That distinction drives the testing you need, whether treatment exists, and how worried to be about long-term liver damage. Both are vaccine-preventable, and both can cause overlapping symptoms during the acute phase, so you can't sort them out by how you feel.
What each one is
Hepatitis A
Hepatitis A is a liver infection caused by the hepatitis A virus (HAV) CDC, About Hepatitis A. It's transmitted through the fecal-oral route by swallowing tiny amounts of stool from contaminated food, water, or close contact, including some sexual practices. It does not cause chronic infection. After an acute illness that can last weeks to a couple of months, the virus clears and you recover completely, usually with lasting immunity. Reported acute cases dropped sharply, from nearly 10,000 in 2020 to about 1,600 in 2023, as the large person-to-person outbreaks of recent years waned.
Hepatitis B
Hepatitis B is a liver infection caused by the hepatitis B virus (HBV), and it's primarily blood-borne and sexually transmitted CDC, About Hepatitis B. Clinicians split it into two phases: acute hepatitis B is the short-term illness in the first six months after exposure, and chronic hepatitis B is infection that persists beyond six months, which can be lifelong. The biggest predictor of whether it becomes chronic is age at infection. Caught in adulthood it turns chronic in under 5% of people; caught in infancy it becomes lifelong in about 90% WHO, Hepatitis B. That's why the birth-dose vaccine matters so much. Acute reports have held roughly steady at about 2,200 a year from 2020 through 2023 CDC surveillance, while hundreds of thousands more live with undiagnosed chronic infection.
Symptoms compared
The symptoms overlap heavily, which is the core problem when you're trying to tell these apart. With hepatitis A, not everyone gets sick. Adults are far more likely to have symptoms than children, and young kids can be infectious with no signs at all. When symptoms do appear, they include fatigue, nausea, abdominal pain, jaundice (yellowing of the skin or whites of the eyes), dark urine, and clay-colored stools.
Acute hepatitis B looks remarkably similar, with fatigue, fever, poor appetite, nausea, abdominal pain, dark urine, clay-colored stools, and jaundice, but it can also bring joint pain, which is a bit more characteristic of HBV. Many people with acute hepatitis B feel nothing at all, and most people with chronic hepatitis B are asymptomatic, so liver damage can build silently for years. For a fuller picture of what to expect over time, see hepatitis a symptoms and how long they last and hepatitis b symptoms.
How to tell them apart
You usually can't tell them apart by feel, and the symptoms overlap enough that a blood test is what settles it. A clinician weighs a few discriminating features:
- Exposure history matters most. A recent foodborne outbreak, travel, or fecal-oral contact points toward hepatitis A; a new sexual partner, blood exposure, or sharing injection equipment points toward hepatitis B.
- Time course is a clue. Hepatitis A symptoms resolve and don't come back. If you have persistent fatigue, abnormal liver tests, or no symptoms but a known exposure, chronic hepatitis B is on the table.
- Hepatitis A never becomes chronic, so a positive test months later means hepatitis B or another cause, not lingering HAV.
- Joint pain leans toward hepatitis B, though it's not reliable enough to diagnose on its own.
Side-by-side comparison
| Feature | Hepatitis A | Hepatitis B |
|---|---|---|
| Virus | Hepatitis A virus (HAV) | Hepatitis B virus (HBV) |
| Main spread | Fecal-oral (food, water, close contact) | Blood-borne and sexual |
| Becomes chronic? | No — always clears | Yes — can be lifelong |
| Vaccine available? | Yes | Yes (including a birth dose) |
| Typical symptoms | Fatigue, nausea, abdominal pain, jaundice, dark urine, clay-colored stools | Same, plus fever and joint pain; often none |
| Treatment | Supportive only | Acute: supportive. Chronic: lifelong antivirals, no cure |
| Diagnosis | Blood test | Triple serologic panel (HBsAg, anti-HBs, anti-HBc) |
Testing
Hepatitis A is confirmed with a blood test that looks for antibodies showing recent infection. Hepatitis B uses a triple serologic panel: HBsAg flags active infection, anti-HBs shows immunity or recovery, and total anti-HBc indicates past or current infection CDC, HBV testing. Reading those three together tells a clinician whether you're currently infected, recovered, vaccinated, or never exposed.
The CDC's 2023 guidance recommends screening all adults aged 18 and older for hepatitis B at least once in their lifetime, and pregnant people each pregnancy CDC, 2023 MMWR. Testing is simple. Depending on what's suspected, you may give a urine sample, a self-collected swab, or have a quick exam, and it's free or low-cost at health departments, Planned Parenthood, and Title X clinics. You can get tested at any of those, and if you're counting days since a possible exposure, check when to test after exposure so you don't test too early to get a reliable result.
Treatment compared
There's no specific antiviral for hepatitis A. Care is supportive, with rest, fluids, and good nutrition while your body clears the virus. Most people recover fully without lasting liver damage.
Acute hepatitis B also usually needs only supportive care, since most adults clear it. Chronic hepatitis B is a different story: there's no cure, but FDA-approved antivirals such as tenofovir or entecavir suppress the virus and cut the risk of liver cancer CDC, HBV treatment. Most people take these medicines for life, and clearance happens in only about 2 to 5% even after a decade of treatment AASLD, 2018. Chronic HBV should be managed by a liver specialist who monitors the virus and screens for liver damage over time.
Can you have more than one at once?
Yes. The hepatitis viruses are distinct, so having one offers no protection against the others, and co-infection is possible. Someone with chronic hepatitis B can still catch acute hepatitis A, and a new hepatitis A infection on top of underlying chronic liver disease can hit harder, which is one reason hepatitis A vaccination is recommended for people who already have hepatitis B. Because past hepatitis A or vaccination usually leaves lasting immunity, a second hepatitis A infection is uncommon, but the two infections are entirely separate events.
When to see a clinician
Get checked if you develop jaundice, dark urine, clay-colored stools, persistent nausea, or unexplained fatigue, especially after a known exposure or a new sexual partner. Don't wait for symptoms if you've had a high-risk exposure, since both infections can be silent early on and hepatitis B vaccination or post-exposure treatment is more useful the sooner it's given. Anyone with ongoing fatigue, abnormal liver tests, or a positive hepatitis B result needs follow-up to determine whether the infection is acute or chronic and whether treatment is needed.