Hepatitis A vs B vs C: How They Spread

Hepatitis A, B, and C are three different viruses that all inflame the liver but spread differently: hepatitis A spreads fecal-orally, including through some sexual contact, and clears on its own; hepatitis B spreads through blood, sex, and birth and can become chronic; hepatitis C spreads through blood and is now curable with pills. Vaccines exist for A and B only.

The three viruses, one line each

• Hepatitis A (HAV): A short-term liver infection spread mostly through the fecal-oral route. It never becomes chronic, people recover fully, and a vaccine prevents it CDC, Hep A.
• Hepatitis B (HBV): A blood-borne and sexually transmitted liver infection. It can stay acute and clear, or become chronic and lifelong. No cure, but a vaccine and suppressive antivirals exist CDC, Hep B.
• Hepatitis C (HCV): A blood-borne liver infection that usually becomes chronic. There's no vaccine, but a short course of pills cures more than 95% of people CDC, Hep C.

How each one spreads

The route of transmission is the single biggest difference between these viruses, and it drives everything else: who's at risk, how you prevent it, and whether sex matters.

Hepatitis A: fecal-oral, including sex

Hepatitis A passes when tiny amounts of stool from an infected person reach another person's mouth: through contaminated food or water, close household contact, or sexual contact that involves the anus (oral-anal contact in particular). That's why outbreaks cluster in settings with shared food or poor sanitation, and why it's counted among sexually transmissible infections even though it's not a classic genital STI. Young children are often infectious while showing no signs at all, so they quietly seed spread to adults around them.

Hepatitis B: blood, sex, and birth

Hepatitis B lives in blood and body fluids and is highly infectious. It spreads through unprotected sex, sharing needles or other drug equipment, and from a pregnant person to the baby at birth, perinatal transmission. The birth route is the most consequential one because of how the body responds to infection at that age, which we'll come back to under chronic infection.

Hepatitis C, almost always blood

Hepatitis C requires blood from an infected person to enter the bloodstream of another. In practice that means sharing injection equipment is the dominant route today; it can also pass through unregulated tattooing or, less commonly, sexual contact involving blood. It's far less efficiently spread by sex than hepatitis B, so the sexual-risk profile of the two is genuinely different.

Acute vs chronic: the divide that matters most

"Acute" means the first six months after exposure; "chronic" means infection that lasts beyond that and can become lifelong. This is where the three viruses split sharply.

Hepatitis A is self-limiting, it doesn't have a chronic form. Your immune system clears it and you recover completely. Hepatitis B can go either way, and age at infection decides it: caught as an adult, it becomes chronic in fewer than 5% of people, but caught in infancy it becomes lifelong in about 90% WHO. That's the entire reason the birth-dose vaccine is treated as urgent. Hepatitis C flips the odds the other way: most people who get infected develop chronic, lifelong infection if they aren't treated CDC clinical.

Why all three are often silent

The liver doesn't have pain nerves in the way the gut does, and these viruses can damage it slowly without producing obvious signals. That's why screening, not waiting for symptoms, is how most chronic cases get caught.

When hepatitis A does cause symptoms, expect fatigue, nausea, abdominal pain, jaundice (yellowing of the skin or eyes from bilirubin the liver can't clear), dark urine, and clay-colored stools; adults show symptoms more often than children. The full arc of what to expect is covered in hepatitis a symptoms. Acute hepatitis B can bring the same picture plus fever, joint pain, and poor appetite, but many people feel nothing, see hepatitis b symptoms for the detail. Hepatitis C is the quietest of the three: jaundice shows up in only about 20–30% of acute infections, vaguer symptoms in maybe 10–20%, and chronic infection often causes nothing noticeable for 20 years or more, until liver scarring is already advanced.

The practical bottom line: the symptoms overlap too much to tell these apart by feel. A blood test is what settles it.

Testing for each

Each virus has its own blood test, and current guidance pushes broad, one-time screening rather than testing only people with symptoms.

• Hepatitis A is confirmed with a single blood test that looks for antibodies to the virus.
• Hepatitis B uses a triple panel. HBsAg (a positive means active infection), anti-HBs (signals immunity or recovery), and total anti-HBc (marks past or current infection). CDC now recommends every adult 18 and older be screened at least once in their lifetime, and pregnant people each pregnancy MMWR, 2023.
• Hepatitis C starts with an antibody test; if it's positive, the lab automatically runs a NAT for HCV RNA to confirm a current, active infection CDC, Hep C dx. CDC recommends screening all adults 18 and older at least once and every pregnancy, and the USPSTF gives a Grade B recommendation for one-time screening in adults aged 18–79 USPSTF.

In real life, testing is a quick blood draw, and depending on what's suspected a clinic may also use a urine sample, a self-collected swab, or a brief exam for related concerns. It's free or low-cost at health departments, Planned Parenthood, and Title X clinics. You can get tested for a full panel, and if you're testing after a specific exposure, check when to test after exposure so you don't test too early to be accurate.

Treatment: supportive, suppressive, or curable

This is the other place the three diverge completely, and it's where being precise about which virus you have changes your whole outlook.

Hepatitis A, supportive care

There's no specific antiviral for hepatitis A. Care is supportive: rest, fluids, and good nutrition while the infection clears on its own. Most people fully recover.

Hepatitis B: controlled, not cured

Acute hepatitis B usually needs only supportive care. Chronic hepatitis B has no cure, but FDA-approved antivirals, tenofovir or entecavir, suppress the virus and cut the risk of liver cancer and scarring CDC, Hep B Tx. The catch is that most people take them for life: true viral clearance happens in only about 2–5% of patients even after a decade of treatment AASLD, 2018. A liver or infectious-disease specialist manages the regimen and monitoring.

Hepatitis C, genuinely curable

Hepatitis C is the success story. An 8–12-week course of oral direct-acting antiviral (DAA) pills cures more than 95% of people, and that cure is durable, it holds in over 99% of people followed five years out WHO. The simplified regimens are concrete: glecaprevir/pibrentasvir for 8 weeks, or sofosbuvir/velpatasvir for 12 weeks, and current guidance recommends treating essentially everyone with HCV rather than waiting for advanced disease AASLD/IDSA. The full picture of who qualifies and what cure means is in hepatitis c cure.

Hepatitis A vs B vs C at a glance

Prevention: vaccines for A and B, none for C

Hepatitis A and hepatitis B both have safe, effective vaccines: the hepatitis A vaccine has helped reported acute cases fall from nearly 10,000 in 2020 to about 1,600 in 2023 as person-to-person outbreaks waned CDC AtlasPlus, 2023. Hepatitis B vaccination, especially the birth dose, is what blocks the high-risk infant route. Hepatitis C has no vaccine, so prevention rests on not sharing needles or equipment, safer sex when blood may be involved, and one-time screening to catch silent infections early.

By the numbers, the gap between reported cases and hidden ones is large for both chronic viruses. Acute hepatitis B reports have held around 2,200 a year, but hundreds of thousands more live with undiagnosed chronic HBV CDC surveillance. Acute hepatitis C reports run around 5,000 a year, yet roughly 2.4 million Americans live with chronic HCV: most unaware CDC, Hep C.

When to see a clinician

Get evaluated promptly if you notice jaundice, dark urine, clay-colored stools, persistent fatigue, or right-upper-abdominal pain, those point to active liver inflammation. See a clinician sooner if you've shared injection equipment, had a needlestick, had sex with someone who has hepatitis B or C, or are pregnant and haven't been screened. And because all three can be silent, getting screened once even when you feel fine is the most reliable move.

For the two sexually transmitted ones head to head, see hepatitis B vs hepatitis C.

Keep exploring on EasySTD: STD vaccines, confidential testing by state and Hepatitis A testing.