HIV Testing Types and Window Periods
According to global health reports, 25% of individuals living with HIV are undiagnosed.
This silent spread of HIV is why regular testing matters. Early testing and treatment can drastically reduce complications, improve quality of life, and virtually eliminate the risk of transmission.
Knowing your status isn’t just a personal responsibility—it’s a step toward breaking the chain of transmission.
What Is HIV Testing?
HIV testing is the only way to confirm if you have HIV. It involves two key steps:
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Screening Test: Quickly identifies possible presence of HIV.
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Confirmatory Test: Verifies positive results.
Screening Test
The first step in HIV testing identifies antibodies, antigens, or genetic material in your blood or oral fluid.
Common methods:
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Rapid HIV tests
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Laboratory-based 4th generation antigen/antibody tests
Why Screening First?
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Fast
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Reliable
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Affordable
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Encourages routine testing for people with multiple partners or inconsistent condom use
Confirmatory Test
If the screening test is positive, follow-up tests confirm the diagnosis:
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Western Blot (rarely used now)
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HIV RNA Test (NAT)
What Happens After a Positive Confirmation?
You’ll undergo further testing:
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Viral Load: Measures the amount of HIV RNA in the blood.
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CD4 Count: Reflects the strength of your immune system (normal range: 500–1,500 cells/mm³).
How Is HIV Testing Done?
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Rapid Tests: Oral fluid or finger-prick blood, results in 20 minutes
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Lab-Based Tests: Venous blood draw, higher accuracy
Types of HIV Tests & Their Accuracy
Types of HIV Tests & Accuracy
| Test Type | What it Detects | Window Period | Notes |
|---|---|---|---|
| Antibody Tests | HIV antibodies | 28–90 days | Most accurate after 3 months |
| 4th Gen Antigen/Antibody | p24 antigen + antibodies | 14–28 days | Conclusive at 28 days |
| HIV RNA (PCR/NAT) | HIV RNA (virus itself) | 7–10 days | Most sensitive, used for early/high-risk cases |
Visit our HIV Testing page for pricing and additional info about getting tested in Singapore.
Why Window Periods Matter
Testing too early can give a false negative. To improve accuracy:
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Test at the right time for the test you’re using
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Repeat testing if exposure was recent
When Should You Get Tested?
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If your partner’s status is unknown
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After unprotected sex or needle sharing
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Following a workplace needle injury
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As part of routine screening (CDC: everyone aged 13–64 at least once)
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Before stopping condom use
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During pregnancy
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If you have a history of STIs
Why Early HIV Testing Is Important
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Start Treatment Early – Begin ART before your immune system is compromised
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Prevent Transmission – Undetectable = Untransmittable (U=U)
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Protect Pregnancies – Prevent mother-to-child transmission
Frequently Asked Questions (FAQs)
Are HIV test kits reliable?
Yes—if used correctly and within the right window period.
Can HIV tests detect AIDS?
No. Tests detect HIV, not AIDS. AIDS is diagnosed by symptoms and CD4 levels.
3rd Gen vs 4th Gen Tests?
4th Gen detects HIV earlier by identifying antigens.
RNA Test vs 4th Gen?
RNA tests are better for early detection but cost more. 4th Gen is more common.
What’s the difference between screening and confirmation?
Screening = initial test. Confirmation = verification of a reactive result.
Where can I get tested?
Hospitals, mobile clinics, and private clinics like Hisential.
Blood test or oral swab – which is better?
Blood tests are more accurate. Oral swabs are convenient but slightly less sensitive.
When do HIV tests become positive?
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RNA test: 10–14 days
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4th Gen test: 2–4 weeks
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Antibody test: 3–12 weeks
Get Tested at Hisential
At Hisential, we provide:
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Rapid and lab-based HIV testing
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Confirmatory diagnostics
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CD4 and viral load monitoring
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Private and affordable care
Click here to see our HIV Testing prices in Singapore.
Recently exposed? You may qualify for PEP if within 72 hours of exposure. Find our more about PEP here.
