References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
HIV (human immunodeficiency virus) attacks the immune system, specifically CD4 T-cells that coordinate the body’s defence against infections. Without treatment, HIV gradually weakens the immune system over years, eventually leading to advanced disease (AIDS). With modern antiretroviral therapy (ART), people with HIV can expect a near-normal lifespan and cannot pass the virus on sexually when their viral load is undetectable (U=U).
Order a discreet home HIV test
Key Facts
| Feature | Detail |
|---|---|
| Cause | Human immunodeficiency virus |
| Transmission | Sex, blood, mother-to-baby |
| Treatment | Lifelong ART — highly effective |
| Cure | Not yet — research ongoing |
| Life expectancy | Near-normal with treatment |
| U=U | Undetectable = Untransmittable |
| PrEP | Over 99% effective prevention |
| UK prevalence | ~106,000 people living with HIV |
How HIV Is Transmitted
- Unprotected vaginal, anal or (rarely) oral sex
- Sharing injecting equipment
- Mother to baby during pregnancy, birth or breastfeeding
- Not through kissing, sharing food, toilet seats or mosquitoes
Symptoms
- Acute: flu-like illness 2-4 weeks after infection (70-80% of people)
- Then usually no symptoms for years
- Late: weight loss, infections, cancers (preventable with treatment)
Testing
- 4th-generation lab test reliable from 4 weeks
- Rapid self-tests available
- Free on NHS
- Home kits widely available
Treatment
- Usually a single daily tablet
- Long-acting injections available
- Suppresses virus to undetectable
- Free on NHS for everyone
Prevention
- Condoms
- PrEP — free on NHS
- PEP within 72 hours of exposure
- U=U — treated HIV can’t be passed on
- Regular testing
Read more: HIV and the immune system | Life expectancy | PrEP
Frequently Asked Questions
Is HIV a death sentence?
No — modern treatment means near-normal life expectancy.
Can I still have sex?
Yes — with treatment, you can’t pass HIV on sexually (U=U).
Is there a cure?
Not yet — but research is active and treatment is excellent.
Related reading
- What Is a Female (Internal) Condom?
- What Is a Shigella Infection?
- What Is Bacterial Vaginosis (BV)?
- What Is Gonococcal Arthritis?
- What Is Human Papillomavirus (HPV)?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
Ready to start treatment?
verified Start Treatment Today arrow_forwardOnline consultation · UK doctors · Discreet delivery
