The stages of HIV explained

HIV attacks the immune system. Without treatment, it usually moves through three stages:

• Early infection: some people get a short flu-like illness 2 to 6 weeks after infection.
• Chronic infection with no symptoms: this can last for years, while the virus keeps damaging the immune system.
• Late-stage HIV (AIDS): the immune system is badly damaged, and serious infections and cancers can develop.

The World Health Organization uses its own four clinical stages, and an older four-stage model splits the middle stage in two. With treatment, most people with HIV never reach the late stage.

The first stage is often called seroconversion, when your body starts making antibodies to HIV. Some people get a short illness around 2 to 6 weeks after infection, which usually lasts 1 to 2 weeks. Symptoms can include:

• a sore throat
• a high temperature
• swollen glands
• muscle aches and tiredness
• a skin rash

These symptoms are easy to mistake for flu or another virus, and not everyone gets them. There’s a lot of HIV in the blood at this stage, so it’s easier to pass on. Read more in “What are the symptoms of seroconversion?”

After early infection, you may not have any symptoms of HIV for years. This is why many people with HIV don’t know they have it.

The virus is still active during this stage. It keeps copying itself and slowly damaging the immune system, and it can still be passed on. Without treatment, this stage may last 10 years or longer, but it can move faster in some people.

A test is the only way to know you have HIV at this stage. Read more in “Is it a cold or HIV? How to tell the difference”

Without treatment, HIV eventually damages the immune system so badly that the body can’t fight off infections. As this happens, symptoms can include:

• weight loss
• night sweats
• long-lasting diarrhoea
• thrush in the mouth
• more frequent cold sores or Herpes outbreaks
• swollen glands and tiredness

Late-stage HIV is also called advanced HIV or AIDS (acquired immune deficiency syndrome). It’s diagnosed when the number of CD4 cells, the immune cells HIV attacks, falls below 200 per cubic millimetre of blood, or when certain serious illnesses develop. These include tuberculosis, pneumonia and some cancers.

Late diagnosis is still common in the UK. In England in 2024, 42% of people newly diagnosed with HIV were diagnosed late, and adults diagnosed late were 10 times more likely to die within a year.

There’s no cure for HIV, but daily antiretroviral medicine keeps it under control. With treatment:

• people who take their treatment as prescribed may never develop AIDS
• most people with HIV can live a long and healthy life
• the amount of virus in the blood usually becomes undetectable within about 6 months
• someone with an undetectable viral load can’t pass HIV on to sexual partners

In England in 2024, 95% of adults living with HIV had been diagnosed, 99% of them were on treatment and 98% of those on treatment had their HIV under control. That’s why testing early matters so much.

You can lower your risk of HIV by:

• using condoms for vaginal and anal sex
• taking PrEP (pre-exposure prophylaxis), a medicine that helps stop you getting HIV if you’re at higher risk
• getting tested regularly, so you and your partners know your status

If you think you were exposed to HIV in the last 72 hours, get urgent medical care straight away and ask about PEP (post-exposure prophylaxis). It works best within 24 hours, and you take it for 28 days.

HIV tests need time after exposure to give a reliable result. UK guidelines say:

• a lab test that looks for HIV antibodies and the p24 antigen (a fourth generation test) is reliable from 45 days
• rapid tests and self-tests are reliable from 90 days
• if you test earlier, a negative result needs a repeat test once that time has passed

Symptoms can’t tell you whether you have HIV, so test after sex without a condom with a new partner, or if a partner tells you they have HIV. UK guidelines recommend a yearly test for sexually active gay, bisexual and other men who have sex with men, and more often for those at higher risk. Read more in “What’s the difference between a window period and an incubation period?”

Better2Know offers:

• HIV test: a blood test for HIV 1, HIV 2 and the p24 antigen, from 28 days after sex, with results in 1 day. If you test before 45 days, a negative result needs a repeat test. You can book it at one of our clinics or order an HIV home test.
• Early Detection Screen: if you want to test sooner, it includes an early HIV test from 10 days after sex, plus Hepatitis B and Hepatitis C, with results in 3 days. A negative early HIV result needs a follow-up test at 45 days.
• Full Screen: tests for 7 infections, including HIV, Chlamydia, Gonorrhoea, Syphilis and Hepatitis B, from 28 days after sex, with results in 3 days. If you test before 45 days, a negative HIV result needs a repeat test. A Syphilis test in the first 3 months after sex can miss the infection, so you may need a repeat test.

Not sure which test you need? Our Patient Care Team is available 24/7 on 020 7099 0955.

How long does it take for HIV to turn into AIDS?

Without treatment, the stage with no symptoms often lasts 10 years or more, but it can be shorter. With treatment, most people with HIV never develop AIDS.

Can you have HIV and feel completely well?

Yes. After early infection, many people have no symptoms for years, which is why testing is the only way to know.

Is there a cure for HIV?

Not yet. But daily treatment keeps HIV under control, lets most people live a long and healthy life, and stops HIV being passed on once the viral load is undetectable.

Without treatment, HIV moves from early infection, through years without symptoms, to late-stage HIV. Treatment stops that happening, so the most important step is finding out early. If you’ve had sex without a condom with a new partner, or you’re worried about HIV, get tested.

Book an HIV test at a clinic near you or order a home test kit from 28 days after sex. Our Patient Care Team is available 24/7 on 020 7099 0955.

Not in the UK? Choose your country from the selector at the top of the page for local tests and prices.

This article originally appeared on 23 October 2020 and was last updated on 30 September 2026.

This article is general information and not a substitute for personal medical advice.

Sources

1. NHS, HIV and AIDS, reviewed 9 July 2025. https://www.nhs.uk/conditions/hiv-and-aids/
2. Terrence Higgins Trust, Symptoms of HIV. https://tht.org.uk/hiv/about-hiv/symptoms-hiv
3. Centers for Disease Control and Prevention, About HIV, reviewed 14 January 2025. https://www.cdc.gov/hiv/about/index.html
4. World Health Organization, HIV and AIDS, 27 July 2026. https://www.who.int/news-room/fact-sheets/detail/hiv-aids
5. UK Health Security Agency, HIV testing, PrEP, new HIV diagnoses and care outcomes for people accessing HIV services: 2025 report, updated 15 April 2026. https://www.gov.uk/government/statistics/hiv-annual-data-tables/hiv-testing-prep-new-hiv-diagnoses-and-care-outcomes-for-people-accessing-hiv-services-2025-report
6. UK Health Security Agency, HIV diagnoses fall in England, 7 October 2025. https://www.gov.uk/government/news/hiv-diagnoses-fall-in-england
7. British HIV Association, BHIVA encourages universal promotion of Undetectable=Untransmittable (U=U), 30 November 2018. https://bhiva.org/BHIVA-encourages-universal-promotion-of-U-U/
8. British Association for Sexual Health and HIV and British HIV Association, UK guideline for the use of HIV post-exposure prophylaxis, 2021, amended 2023. https://bhiva.org/wp-content/uploads/2024/10/PEP-guidelines.pdf
9. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines, 2020. https://bhiva.org/wp-content/uploads/2024/10/HIV-testing-guidelines-2020.pdf
10. British HIV Association, British Association for Sexual Health and HIV and British Infection Association, Adult HIV testing guidelines 2020: non-technical summary. https://bhiva.org/wp-content/uploads/2024/10/BHIVA-Testing-guidelines-non-technical.pdf
11. British Association for Sexual Health and HIV, UK guidelines for the management of syphilis, 2024. https://bashh.org/_userfiles/pages/files/syphilis_2024.pdf