STI TEST · BANGKOK
Hepatitis B Test in Bangkok
A hepatitis B blood test with a doctor who comes to you in Bangkok, to check for current infection and whether you are protected by vaccination.
Message Ovio Medically reviewed by Kewalee Rujikajorn, MD · 24 September 2026
Hepatitis B test at a glance.
- SampleBlood
- Detectable from1–12 weeks after exposure
- SymptomsOften none, even when chronic
- PreventionA highly effective vaccine
- Who comesA doctor, to your home, condo, hotel or office
- ResultsExplained by your doctor
- PriceConfirmed before your visit
THE INFECTION
What is hepatitis B?
- Cause
- A virus that infects the liver
- Also called
- HBV infection · Hepatitis B virus
Hepatitis B is a viral infection of the liver, caused by the hepatitis B virus (HBV). It passes through blood and body fluids: during sex without a condom, from mother to baby at birth, and through shared needles, razors or unsterile medical, tattoo or piercing equipment.
In adults, most new infections clear by themselves within six months. Some become chronic, lasting for life, and chronic hepatitis B can slowly damage the liver for decades without symptoms before causing cirrhosis or liver cancer. Worldwide only around a quarter of people living with hepatitis B know they have it.
Hepatitis B is the only common STI with a highly effective vaccine. A blood test can tell you three different things: whether you have it now, whether you have had it in the past, and whether you are protected by vaccination. That makes it one of the most useful tests to have at least once as an adult.
Symptoms of hepatitis B.
Many adults have no symptoms when they are first infected. When symptoms appear, it is usually one to four months after exposure.
New (acute) infection
- Yellow skin or eyes (jaundice)
- Dark urine and pale stools
- Tiredness, nausea and vomiting
- Pain under the right ribs
Long-term (chronic) infection
- Usually no symptoms for years
- Tiredness
- Later, signs of liver damage
- Found by a blood test or a liver check
Chronic hepatitis B is usually silent until the liver is damaged. A blood test is the only way to find it early.
How the hepatitis B test works.
Hepatitis B is diagnosed with blood tests. A doctor chooses the markers based on why you are testing, and reads them together.
HBsAg (surface antigen)
Blood
The main test for current infection. Positive for more than six months means chronic hepatitis B.
Anti-HBs (surface antibody)
Blood
Shows immunity, from vaccination or a cleared infection, and whether a vaccine is needed.
Anti-HBc (core antibody)
Blood
Shows infection at any time in the past or present. Not produced by vaccination.
Sources: CDC2, Thailand Department of Disease Control3, WHO1
Testing with Ovio
- Tell us what you needCall or message Ovio, privately. Say where you are in Bangkok and when suits you.
- A doctor comes to youAt your home, condo, hotel or office. The doctor asks about your concerns and recommends the right samples.
- Samples go to the laboratoryTaken there and then; for most tests the visit itself is short.
- Your result, explainedWhat it means, and what to do next if anything needs treatment or a repeat test.
Not sure which test you need?
Speak to one of our doctors. They will ask about your situation and suggest the tests, samples and timing that fit it.
When to test for hepatitis B.
Every test has a window period: the time after exposure before it can reliably detect an infection. A test taken too early can be negative even when the infection is there.
| Test | Sample | Timing after exposure | Good to know |
|---|---|---|---|
| HBsAg and other markers chosen by a clinician | Blood | Usually detectable 7–84 days | CDC states HBsAg may appear from 1–2 to 11–12 weeks. Recent exposure may also require urgent vaccine/immune-globulin assessment. |
Who should get tested
- Every adult at least once, especially if born where hepatitis B is common
- Anyone not sure they completed the vaccine course
- Anyone with a partner or household member who has hepatitis B
- Anyone with a new partner or more than one partner
- Anyone living with HIV, or starting PrEP
- Everyone who is pregnant
AFTER THE TEST
Results and next steps.
If HBsAg is negative and you are not immune, the doctor will recommend vaccination. If you are immune, no further action is needed.
If HBsAg is positive, further blood tests show how active the virus is and how healthy the liver is. Many people with chronic hepatitis B need monitoring rather than immediate treatment; those who need treatment take daily antiviral tablets that keep the virus under control.
Close contacts and sexual partners should be tested and vaccinated if they are not already protected.
This page is general information, not a diagnosis. If you are unwell, in severe pain or worried about something urgent, contact a doctor now or go to a hospital emergency department.
Lowering your risk.
- Complete the hepatitis B vaccine course if you are not immune
- Use condoms, especially with new partners
- Never share needles, razors or toothbrushes
- Choose licensed tattoo, piercing and beauty clinics
- After a possible exposure, see a doctor within days about a vaccine dose
Hepatitis B testing:
your questions.
Can't see your question? Ask one of our doctors.
HBsAg (surface antigen) positive means you have hepatitis B now. Anti-HBs (surface antibody) positive means you are protected, either from vaccination or from a past infection that cleared. Anti-HBc (core antibody) positive means you have been infected at some point. Doctors read the three together, so a single number rarely tells the whole story.
Vaccination gives long-lasting protection for most people, at least 20 years according to the World Health Organization. A test can still be useful if you are not sure the course was completed, if you are at higher risk, or before starting PrEP or certain medicines. An anti-HBs result shows whether you are protected.
HBsAg usually becomes detectable between 1 and 12 weeks after infection. If you might have been exposed recently and are not vaccinated, see a doctor within days rather than waiting to test: a vaccine dose, sometimes with immune globulin, given soon after exposure can prevent infection.
It can be. Hepatitis B passes easily through sex without a condom, and the World Health Organization notes sexual transmission is most common in unvaccinated people with more than one partner. It is also spread in other ways, such as at birth or through shared needles.
Most adults clear a new infection naturally. Chronic hepatitis B is not usually cured, but daily antiviral tablets such as tenofovir or entecavir control the virus very well and greatly reduce the risk of cirrhosis and liver cancer. Regular monitoring with a doctor is part of living well with it.
MEDICALLY REVIEWED
Kewalee Rujikajorn, MD
General Practitioner, Bangkok
Reviewed 24 September 2026
Kewalee Rujikajorn is a general practitioner in Bangkok, providing outpatient care for urgent, acute and chronic illness and remote consultations through a telemedicine platform. A graduate of the Medical University of Lublin, Kewalee completed postgraduate medical training at Thammasat University Hospital and has published research in ophthalmology.
Sources.
- Hepatitis B: fact sheetWorld Health Organization, 28 July 2026
- Pink Book, Chapter 10: Hepatitis BUS Centers for Disease Control and Prevention
- National Guideline on HIV, Syphilis, HBV and HCV Testing (2025)Thailand Department of Disease Control
- Hepatitis B postexposure prophylaxisUS Centers for Disease Control and Prevention
Ovio uses official public-health sources and reviews this page when they change. Questions about this content: info@oviowellness.com.
Speak to one of our doctors.
A doctor comes to your home, condo, hotel or office in Bangkok, talks through what you are worried about, takes the samples for your hepatitis B test and explains what happens next.