Hepatitis B and C: The Silent Liver Infections Worth Testing For

Of all the infections worth knowing about, hepatitis B and C are the ones people most often carry without realising. Both are viruses that infect the liver, both can settle in for years or decades, and both frequently cause no symptoms at all while quietly raising the risk of serious liver disease. That sounds alarming, but the headline is genuinely hopeful: hepatitis B is preventable with a vaccine, hepatitis C is now curable with a short course of tablets, and a simple blood test is all it takes to know where you stand. This guide explains how they differ, why testing matters — particularly in this region — and what to do about it. It sits alongside our broader guide on STDs in Thailand and why testing matters.

What hepatitis B and C actually are

"Hepatitis" just means inflammation of the liver, and several different viruses can cause it. The two that matter most for long-term health are hepatitis B (HBV) and hepatitis C (HCV), because these are the ones that can become chronic — a long-term infection that persists rather than clearing ³⁴. Over years, chronic infection can slowly scar the liver (cirrhosis), impair its function, and substantially raise the risk of liver cancer ¹. The damage is usually gradual and silent, which is exactly why these infections are easy to miss until late.

The crucial, reassuring difference: hepatitis B is vaccine-preventable, and hepatitis C is curable in the great majority of people. More on both below.

How they spread — and how they differ

Although they affect the same organ, B and C travel somewhat differently:

• Hepatitis B spreads through blood and bodily fluids — including sexual contact, shared needles, and, very importantly in this region, from mother to child at birth ¹³. Infection acquired at birth or in early childhood is far more likely to become lifelong, which is why infant vaccination matters so much.
• Hepatitis C spreads mainly through blood-to-blood contact — shared needles, unsterile medical, dental or tattoo equipment, and (before modern screening) transfusions. Sexual transmission is possible but less common than with B ²⁴.

The scale — and why Thailand matters

This is not a rare problem. The WHO estimates that 254 million people live with chronic hepatitis B, and that hepatitis B causes more than a million deaths a year, mostly from cirrhosis and liver cancer ¹. Thailand sits in a region historically hit hard: it was once classed as "hyper-endemic" for hepatitis B. The turning point was introducing universal infant hepatitis B vaccination in the early 1990s, which dramatically cut infection rates in younger generations — a genuine public-health success ⁵. The catch is that adults born before that programme never had that protection, so older residents carry a higher burden, and many don't know it ⁵.

For visitors and expats there's a practical implication: the CDC recommends hepatitis A and B vaccination for travellers to Thailand ⁶. If you're living here, confirming you're immune to hepatitis B — and getting vaccinated if you're not — is one of the simplest protective steps you can take.

The good news: B is preventable, C is curable

Two facts deserve to be stated plainly, because they change how worried anyone needs to be:

• Hepatitis B is vaccine-preventable. The vaccine is safe, widely available, and offers close to 100% protection when the full course is completed ¹. There's no cure for established chronic hepatitis B, but it can be effectively controlled with antiviral medicine and monitoring, keeping the liver healthy.
• Hepatitis C is curable. Modern direct-acting antiviral tablets cure more than 95% of people in a course of roughly 8–12 weeks, with few side effects ². There's no vaccine for C yet, so testing is how it's found — but once found, it's one of the more treatable chronic infections in medicine.

Why testing matters so much

Here is the thread that ties it together: both infections are usually silent for years, so you can carry chronic hepatitis B or C, feel completely well, and only discover it once the liver is already damaged ³⁴. A blood test removes that uncertainty. Finding hepatitis B early means you can be monitored and treated before damage builds, and your close contacts can be vaccinated; finding hepatitis C early means it can simply be cured.

One important nuance for anyone who's had a check-up: routine liver function tests can look normal even when one of these infections is present. Standard liver enzymes aren't a substitute for the specific hepatitis blood tests — a point we explain in our guide to liver function tests. If you want hepatitis B and C checked, it's worth asking for them by name as part of a screen, much as you would when planning any blood work.

What we see at the clinic

In practice, the patients who handle hepatitis best are the ones who treat it as information, not fate. A test result tells you what to do next — vaccinate, monitor, or in the case of hepatitis C, cure it — and most people are reassured by how manageable both have become. We keep testing straightforward and confidential, explain what each result means, and make sure hepatitis B immunity is something you actually know about rather than assume.

Common questions

Can I have hepatitis B or C and feel completely fine? Yes — this is the usual situation. Both are often symptom-free for years while quietly affecting the liver, which is exactly why a blood test, rather than how you feel, is the only reliable way to know ³⁴.

Is there a vaccine? For hepatitis B, yes — a safe, highly effective one ¹. For hepatitis C there is no vaccine yet, so avoiding blood-to-blood exposure and getting tested are the main protections ².

Is hepatitis C really curable? Yes. Direct-acting antiviral tablets cure more than 95% of people in about 8–12 weeks — a genuine cure, not just control ².

Should I be tested if I live in or have travelled in Thailand? It's sensible. Thailand was historically high-prevalence for hepatitis B, especially among adults born before universal infant vaccination ⁵, and hepatitis vaccination is recommended for travellers ⁶. A one-off screen (and confirming hepatitis B immunity) is a reasonable baseline for residents and long-stay visitors.

My liver tests were normal — doesn't that rule it out? No. Routine liver enzyme tests can be normal even with chronic hepatitis B or C. You need the specific hepatitis blood tests to know — see our guide to liver function tests ³.

Are hepatitis B and C sexually transmitted? Hepatitis B is efficiently transmitted through sex and is a standard part of a full sexual-health screen ¹³. Hepatitis C is mainly blood-borne, with sexual transmission much less common ²⁴.

Key takeaway

Hepatitis B and C earn their "silent" reputation: they can damage the liver for years without a symptom, they're common in this part of the world, and most people who have them don't know. But the story ends well if you act on it. Hepatitis B is prevented by a safe, near-100%-effective vaccine; hepatitis C is cured in most people by a short course of tablets; and a single blood test is all that stands between not knowing and doing something about it. If you live in or travel through Thailand, get screened, confirm you're protected against B, and treat it as the routine, empowering health check it is.