What are the symptoms of HIV?

HIV, or human immunodeficiency virus, is a virus that weakens the immune system, making it harder to fight infections and illness. Without treatment, it can gradually damage the immune system over several years and lead to AIDS, a later stage of the infection.

There's no cure yet, but treatment is highly effective. It stops HIV progressing to AIDS, and with the right care, people with HIV can have a similar life expectancy to people without it. Treatment can also bring HIV in the blood down to an undetectable level, at which point it can't be passed on through sex. Early symptoms, when they happen, can feel like a flu-like illness, and some people have none at all. Symptoms alone can't confirm or rule out HIV, so the only way to know for sure is a test.

What are the early symptoms of HIV?

Early HIV symptoms can appear 2 to 6 weeks after infection and can take the form of a short flu-like illness. When they do happen, they usually clear up within two to three weeks.

Symptoms can include:

• A high temperature
• A sore throat
• Swollen glands
• Aching muscles
• Tiredness
• A skin rash
• Mouth ulcers
• Weight loss

More than six in ten people with HIV notice at least one of these symptoms shortly after infection. But the same symptoms fit plenty of other illnesses too, and some people get none at all.

During this early period, the amount of HIV in the blood is particularly high, which makes the virus easier to pass on than at other times. Starting treatment as soon as HIV is diagnosed brings this down and helps protect the immune system.

Can you have HIV with no symptoms?

Yes. You can have HIV without any noticeable symptoms, and this symptom-free stage can last for years.

After any early flu-like symptoms have passed, you may feel completely well even though HIV is still in the body. Some people do not realise they have HIV for a long time because there may be no obvious signs to notice.

Having no symptoms does not mean HIV has gone away. The virus can still affect the immune system and, without effective treatment, can still be passed on to other people.

The only way to know your HIV status for sure is to test. You can test at a sexual health clinic or use an at-home HIV test if you would prefer to check privately.

What are the symptoms of late-stage HIV?

The symptoms of late-stage HIV, also called advanced HIV or AIDS, develop when HIV has gone untreated for a long time and damages the immune system enough to cause more serious illness, such as tuberculosis, pneumonia or cancer.

Symptoms and complications of late-stage HIV can include:

• Ongoing tiredness
• Night sweats
• Prolonged diarrhoea
• Weight loss
• Thrush or other recurring infections
• Skin problems
• Joint pain

With effective HIV treatment, most people with HIV don't progress to AIDS. AIDS most often develops in people diagnosed very late, after living with untreated HIV for many years. Even if someone is diagnosed at a late stage, treatment can still control HIV, help the immune system recover, and treat many of the illnesses it causes.

What's the difference between HIV and AIDS?

HIV is the virus itself. AIDS is the most advanced stage of HIV, which can develop if the virus goes untreated for a long time and severely damages the immune system.

At this stage, HIV has caused enough damage that a group of serious illnesses can develop, and the body struggles to fight them off. With effective treatment, most people with HIV never develop AIDS, which is also called late-stage or advanced HIV.

Does HIV always turn into AIDS?

No. HIV does not always turn into AIDS if you get treatment. In the UK, most people who are diagnosed with HIV and receive treatment do not develop AIDS.

Modern antiretroviral treatment keeps the amount of virus in the blood low enough to protect the immune system, which is why this later stage has become far less common among people who are diagnosed and stay on treatment. Getting diagnosed is the first step, since treatment can only start once you know your HIV status.

When should you get tested for HIV?

You should get tested for HIV as soon as possible after any possible exposure, and treat it as urgent if the exposure was within the last 72 hours, since emergency medicine called PEP (post-exposure prophylaxis) can only help within that window. Outside of an urgent exposure, testing is simply the only way to know your HIV status for sure, whether or not you have symptoms.

If you think you may have been exposed in the last 72 hours, don't wait to test first: contact a sexual health clinic or go to A&E straight away.

If the exposure was more than 72 hours ago, you can go ahead and take an HIV test. Testing is available free through the NHS, using either a blood or saliva sample. A clinic sample usually goes to a lab and takes a few days to come back, while a home testing kit can often give a result within minutes.

If the exposure was recent, you may be advised to test again a few weeks later. A healthcare professional can tell you when to retest based on the test you've used.

Frequently asked questions

How soon do HIV symptoms appear after infection?

Early symptoms, if they appear, can show up 2 to 6 weeks after infection and usually clear up within two to three weeks. Plenty of people don't notice any symptoms at this stage.

Can you have HIV with no symptoms at all?

Yes. HIV can cause no symptoms at all for years, so many people with HIV don't know they have it. The virus can still affect the immune system in the background, and it can still be transmitted to other people during this time. Testing, not symptoms, is the only way to know your status for sure.

What's the difference between HIV and AIDS?

HIV is the virus. AIDS is the name for the late stage of HIV, when the immune system has become seriously damaged without treatment. Most people with HIV on treatment in the UK never reach this stage.

Does HIV always progress to AIDS?

No. Most people who receive HIV treatment do not progress to AIDS.

Is HIV curable?

There's no cure for HIV yet, though treatment works extremely well. It can lower the amount of virus in the blood until it's undetectable, protecting long-term health and stopping transmission through sex.

When should I get tested after a possible exposure?

Test as soon as you reasonably can. If the possible exposure was very recent, you may be advised to test again a few weeks later to be sure. If it was within the last 72 hours, PEP may also be an option, so it's worth contacting a sexual health clinic or A&E promptly rather than waiting.

References

• Centers for Disease Control and Prevention. "About HIV." CDC, 14 Jan. 2025, cdc.gov/hiv/about/index.html.
• GOV.UK / UK Health Security Agency. "New HIV Report Shows Progress but Inequalities Persist in Access to Testing, PrEP and Early Diagnosis." GOV.UK, 14 May 2026, gov.uk/government/news/new-hiv-report-shows-progress-but-inequalities-persist-in-access-to-testing-prep-and-early-diagnosis.
• NHS. "HIV and AIDS." NHS.uk, 9 Jul. 2025, nhs.uk/conditions/hiv-and-aids.

Show all references

• Terrence Higgins Trust (aidsmap). "Early HIV Infection." aidsmap, Nov. 2025, aidsmap.com/about-hiv/early-hiv-infection.
• Terrence Higgins Trust (aidsmap). "The Stages of HIV Infection." aidsmap, Jun. 2025, aidsmap.com/about-hiv/stages-hiv-infection.
• Terrence Higgins Trust. "PEP (Post-Exposure Prophylaxis for HIV)." tht.org.uk, 11 Jun. 2026, tht.org.uk/hiv/protection/pep-post-exposure-prophylaxis-hiv.