How long does it take to show symptoms of HIV?

If you get early symptoms, they usually start 2 to 6 weeks after you catch HIV. The NHS describes a short, flu-like illness around 2 to 6 weeks after infection. It’s sometimes called seroconversion illness, and it usually lasts a week or two.

Not everyone gets it. The NHS says some people do, and that the symptoms of HIV are different for everyone. HIV i-Base, a UK treatment information charity, estimates that up to 4 in 5 people have symptoms and 1 in 5 have none.

Once this illness passes, you may not have any other symptoms for years. The NHS says this means many people with HIV don’t know they have it.

The table shows what can happen, and what you can do, at each point after a possible risk.

Read more in “What’s the difference between a window period and an incubation period?”

Like a short bout of flu. The NHS lists:

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

The NHS adds that these symptoms can also be caused by lots of common conditions, so having them doesn’t mean you have HIV. UK health pages give one list of early symptoms for everyone, with no separate lists for men and women.

This early stage is also when HIV is most easily passed on. Terrence Higgins Trust says it’s when someone with HIV is at their most infectious, and HIV i-Base warns that during this time a person can be very infectious and still test negative. Read more in “Is it a cold or HIV? How to tell the difference” and “What are the symptoms of seroconversion?”

Because some people get none, and the symptoms you might get look like other illnesses. The NHS says many STIs have no symptoms, and HIV can go unnoticed for years. HIV i-Base puts it simply: symptoms are not a reliable way of diagnosing HIV.

The figures for England show what that means:

• About 1 in 20 people with HIV don’t know they have it. An estimated 6,000 adults, out of about 114,000 living with HIV, were undiagnosed in 2024.
• More than 4 in 10 are diagnosed late. In 2024, 42% of adults newly diagnosed with HIV were diagnosed at a late stage, after the virus had already damaged their immune system.
• A late diagnosis is dangerous. Adults diagnosed late in 2023 were ten times more likely to die within a year than those diagnosed promptly.

Read more in “Can you have HIV for a long time and not know it?”

You may feel completely well for years, but the virus stays active. HIV attacks CD4 cells, a type of white blood cell that helps your immune system fight infections. NHS inform says that after the early symptoms disappear, HIV may not cause symptoms for many years, and that during this time it continues to be active and causes damage to your immune system.

Without treatment, later symptoms can include:

• weight loss
• chronic diarrhoea
• night sweats
• skin problems
• infections that keep coming back

In time, untreated HIV can cause serious illnesses such as tuberculosis, pneumonia or cancer. The NHS says this is known as advanced HIV, late-stage HIV or AIDS. With the right treatment, most people with HIV don’t go on to develop it. Read more in “The stages of HIV explained”

A lab blood test is reliable 45 days after a risk, and a rapid test or self-test at 90 days. You can test earlier, but a negative result will need repeating. The time a test needs is called its window period. UK guidelines give these window periods:

• 4th generation lab tests: 45 days. These look for HIV antibodies and for the p24 antigen, part of the virus itself.
• 3rd generation lab tests: 60 days. These look for antibodies only.
• Rapid tests and self-tests: 90 days.

UK guidelines recommend a 4th generation lab test on a blood sample from a vein as the first choice. Most infections show up well before the window period ends. HIV i-Base says a 4th generation test finds 95% of infections at 4 weeks and 99% at 6 weeks.

Tests that look for the genetic material of the virus, called RNA or PCR tests, can find HIV sooner still. UK guidelines don’t recommend them for routine diagnosis, and a negative result this early doesn’t rule HIV out, so you’ll still need a 4th generation test at 45 days.

If the risk was in the last 72 hours

PEP is more urgent than any test. It’s a 28-day course of HIV medicine that can stop you getting infected. It should be started as soon as possible, preferably within 24 hours, and isn’t recommended after 72 hours, so get urgent medical care. If you take PEP, UK guidelines recommend an HIV test at least 45 days after you finish the course. Read more in “What is PEP and how does it work?”

A single positive result isn’t a diagnosis. The NHS says you’ll need a second blood test at a clinic. UK guidelines say a rapid test always has to be confirmed in a laboratory. If the second test is also positive, you’ll be referred to an HIV clinic for more tests and to discuss treatment. UK standards say you should be fully assessed within 2 weeks of a positive result.

Treatment is recommended for everyone with HIV, as soon as they can start after diagnosis. It’s usually tablets taken every day. The NHS says that it usually takes around 6 months of daily medicine for the virus to become undetectable, and that someone on effective treatment with an undetectable viral load can’t pass HIV on. This is known as U=U, undetectable equals untransmittable.

With treatment, most people with HIV live a long and healthy life.

Better2Know offers:

• HIV 4th Generation: a lab blood test for HIV antibodies and the p24 antigen, from 28 days after a risk, with results in 1 day. You can book it at one of our clinics or order a home test kit.
• HIV 1 PCR: a blood test that looks for the genetic material of HIV-1, from 10 days after a risk, with results in 1 day. You can book it at a clinic or have a nurse visit you. A negative result this early needs a follow-up 4th generation test at 45 days.
• Instant 4th Generation HIV test: a rapid test at selected clinics, with results within 20 minutes. UK guidelines say a negative result from a rapid test is only final from 90 days after the risk. A reactive result is confirmed with a lab test, which is included.
• Full Screen: tests for 7 infections, including HIV, Syphilis, Hepatitis B, Chlamydia and Gonorrhoea, from 28 days after sex, with results in 3 days (5 days for the home test).

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.

Can you have HIV for years without symptoms?

Yes. The NHS says you may not have any symptoms for years after the early illness. The National AIDS Trust says people who are diagnosed late have been living with undiagnosed HIV for around three to five years on average.

If I have no symptoms after 6 weeks, am I in the clear?

No. Some people get no early symptoms at all, so feeling well doesn’t rule HIV out. A 4th generation lab test from 45 days after the risk will tell you.

Are early HIV symptoms different in women and men?

UK health pages give the same list of early symptoms for everyone. Read more in “Are HIV symptoms in women different than in men?”

HIV symptoms, if they come at all, usually show 2 to 6 weeks after infection and pass within a week or two. After that, HIV can stay silent for years. That’s why the answer to a possible risk is a test at the right time, and PEP if the risk was in the last 72 hours.

Book an HIV 4th Generation test at a clinic near you or order a home test kit. 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 20 March 2026 and was last updated on 5 October 2026.

Medical review. This article was medically reviewed by Dr Steve Chapman, Doctor with a wealth of clinical experience in the field of STIs, on 13 July 2026. It is general information and not a substitute for personal medical advice.

Sources

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