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Most people who search for this have had a condom break, a night they regret, or a new partner, and now they have a sore throat and a temperature. Googling symptoms rarely helps, because the early signs of HIV are vague and overlap with half a dozen everyday illnesses. Below we go through what the studies show, which signs are common and which aren't, and the point at which a test will actually give you an answer.
What Is Usually the First Sign of HIV?
The first sign of HIV is usually a fever. It tends to arrive as part of a short, flu-like illness about 2 to 4 weeks after infection, often together with tiredness, aching muscles and a headache. Doctors call this stage acute HIV infection (or acute retroviral syndrome). It's the immune system reacting as the virus multiplies quickly in the first few weeks.
When researchers in San Diego followed people diagnosed at this very early stage, 77% of those with symptoms had a fever, and 70% had muscle aches and tiredness. A European study of 218 people back in 1997 found fever in exactly the same proportion, 77%, so the finding has held up.
Early Signs of HIV: The Full List of Symptoms
The 1st symptoms of HIV tend to turn up together. People who get symptoms usually have three or four of the signs below at once. The table comes from a 2016 study (Hoenigl et al.) of 69 people with symptomatic acute HIV. Other studies give somewhat different percentages, though fever stays at the top in nearly all of them.
| Early sign or symptom | Share of people with symptoms |
|---|---|
| Fever | 77% |
| Muscle aches | 70% |
| Tiredness (fatigue) | 70% |
| Headache | 61% |
| Night sweats | 55% |
| Sore throat | 49% |
| Nausea, vomiting or diarrhoea | 42% |
| Rash | 28% |
| Weight loss of more than 2.5 kg | 22% |
| Joint pain | 20% |
One caveat: everyone in that study was a man who has sex with men, so the numbers may not carry over exactly to other groups. HIV.gov and the NHS list the same core signs, and both add swollen glands and mouth ulcers, which the study didn't count separately.
1. Fever
A temperature, often with chills, is the most common early sign of HIV. It can last a few days and may come and go. By itself a fever tells you almost nothing (almost every infection causes one). It's more telling when it arrives with some of the signs below, two to six weeks after a possible exposure.
2. Tiredness and aching muscles
People often describe feeling completely wiped out, with aching muscles and sometimes sore joints, a lot like the start of flu. The exhaustion can hang around longer than it would after an ordinary cold.
3. Headache
A headache usually comes along with the fever. Occasionally early HIV affects the nervous system and causes a severe headache with a stiff neck or a dislike of bright light. If that happens, get seen urgently, whatever you think is causing it.
4. Night sweats
Waking up drenched, sometimes badly enough to change the sheets, was reported by just over half of the people with symptoms in the 2016 study.
5. Sore throat and swollen glands
A sore throat is common, as are tender, swollen glands (lymph nodes) in the neck, armpits or groin. The glands can stay a little enlarged for a while after everything else has settled.
6. A rash
The HIV rash is usually a scattering of small red or pink spots, flat or slightly raised, mostly on the chest, back and face. It often doesn't itch. Only about a quarter of people with symptoms had it in the 2016 study, against more than half in the 1997 one, so plenty of people never get it. If the rash is on your palms and the soles of your feet, think of secondary syphilis too. It's one reason we'd test for more than HIV.
7. Mouth ulcers
Painful sores can appear in the mouth, and sometimes on the genitals or around the anus. On their own they're usually nothing. With a fever and a rash a few weeks after a possible exposure, a doctor will want to test for HIV.
8. Stomach upset and weight loss
About four in ten people with symptoms had nausea, vomiting or diarrhoea, and roughly one in five lost more than 2.5 kg while they were ill.
How Soon Do HIV Symptoms Appear?
Most guidance puts the earliest sign of HIV infection at 2 to 4 weeks after exposure. The NHS gives a slightly wider range of 2 to 6 weeks. The illness usually lasts from a few days to a few weeks: in the 2016 study the median was 8 days. After that the symptoms clear up by themselves, but the virus stays.
Roughly, this is how the weeks after an exposure play out:
0–72 hours: No symptoms and no test can detect HIV yet. This is the window for PEP, a short course of HIV medicine that can prevent infection. Start it as soon as possible.
First 1–2 weeks: Usually no symptoms. The virus is multiplying, but most tests cannot detect it yet.
2–4 weeks (up to 6): The acute illness may begin: fever, tiredness, aching muscles, headache, sore throat, swollen glands, rash or mouth ulcers.
A few days to a few weeks later: The symptoms settle without treatment. This does not mean the infection has cleared.
Months to years: Chronic HIV. Without treatment, many people have no symptoms, or only swollen glands, for a decade or more while the virus slowly damages the immune system.
If you started feeling ill a day or two after the exposure, HIV is an unlikely cause, because the virus hasn't had time to build up. Anxiety, another infection or plain bad timing are far more likely. You should still ask about PEP if you're inside the 72 hours.
Can You Have HIV With No Symptoms?
Yes. HIV.gov estimates that about two-thirds of people have a flu-like illness in the first weeks, which means a substantial minority notice nothing at all. And many who do get ill never connect it with HIV. In the 2016 study, only 29% of people with symptoms went to a doctor about them.
Once the early illness passes, HIV settles into a chronic stage that can stay silent for years. The NHS points out that this is why so many people with HIV don't know they have it. Feeling well says nothing about your HIV status; a test does.
Early HIV Symptoms or Something Else?
No symptom belongs only to early HIV. In Bangkok especially, a fever is far more likely to be flu, COVID-19 or dengue. These are the illnesses most often confused with it:
| Illness | Overlap with early HIV | What can differ |
|---|---|---|
| Flu or COVID-19 | Fever, aches, tiredness, sore throat, headache | Cough and a runny nose are more prominent; a rash and mouth ulcers are unusual |
| Glandular fever (mononucleosis) | Fever, sore throat, swollen glands, tiredness | Very sore throat with swollen tonsils; a blood test can tell them apart |
| Dengue | High fever, headache, muscle and joint pain, rash | Pain behind the eyes; a clear link to mosquito bites rather than sexual exposure |
| Secondary syphilis | Rash, fever, swollen glands, mouth sores | Rash often on the palms and soles; diagnosed with a syphilis blood test |
| Strep throat | Fever, sore throat, swollen neck glands | No rash on the body in most cases; treated with antibiotics |
So what points towards HIV is less the symptoms themselves than when they started and what came before. A flu-like illness, especially with a rash or mouth ulcers, 2 to 6 weeks after sex without a condom, a split condom or shared needles, is worth a test. At that point, book one rather than reading further.
Are Early Signs of HIV Different in Men and Women?
No. Men and women get the same early symptoms: fever, tiredness, aches, sore throat, swollen glands, rash and mouth ulcers. Differences only show up later, if HIV goes untreated and the immune system weakens. Women may then get thrush or other gynaecological infections that keep coming back. Those are late signs, though, and they have plenty of other causes.
Later Signs of HIV: Chronic HIV and AIDS
A lot of articles on the early signs of HIV mix in symptoms that only appear years down the line, which makes them more frightening than they need to be. Left untreated, HIV slowly wears down the immune system, and the World Health Organization lists these later signs:
- Swollen lymph nodes that don't go away
- Weight loss without trying
- Fever and night sweats that keep returning
- Diarrhoea that lasts for weeks
- A persistent cough
The most advanced stage is AIDS, when serious infections and cancers take hold, such as tuberculosis, severe bacterial infections, cryptococcal meningitis, lymphoma and Kaposi's sarcoma. People who are tested and treated rarely get anywhere near this stage.
Why Recognising Early HIV Matters
- You're most infectious now. There's a lot of virus in the blood during acute HIV, so it passes on more easily, usually before anyone knows they have it.
- Earlier treatment is better treatment. Antiretroviral therapy (ART) stops the virus multiplying and protects the immune system. People who start it and stay on it can expect a long, healthy life.
- Undetectable means untransmittable. The World Health Organization is clear that people on treatment with no detectable virus in their blood don't pass HIV to sexual partners.
What to Do If You Think You Have Early HIV Symptoms
If the possible exposure was in the last 72 hours
If it was more than 72 hours ago
- Get tested, and say you have symptoms. Symptoms can begin before every test can detect HIV. A laboratory 4th generation test can usually detect HIV 18 to 45 days after exposure, and an HIV RNA test from 10 to 33 days. If you are unwell, a doctor may suggest an RNA test as well. Read more about the window period in our guide to the 4th generation HIV test.
- Repeat the test if it was early. A negative inside the window period can't rule out a recent infection. Your doctor will give you a date for the next one.
- Check for other STIs while you're at it. Syphilis, gonorrhoea and chlamydia spread the same way, and syphilis in particular can look similar.
- Protect partners until you know. Use condoms, or hold off on sex, until you have a result you can trust.
- Get seen quickly if you're very unwell, for example with a very high fever, a bad headache and stiff neck, confusion or trouble breathing.
HIV Testing in Bangkok
We offer a private HIV test anywhere in Bangkok. A doctor comes to your home, condo, hotel or office, takes the sample, and goes through the result with you, including whether you need another test and when.
Want to check for more than HIV? Our guide to STD testing in Bangkok covers the full panel. And if you're curious about the bigger picture, our Thailand HIV statistics report tracks how HIV is changing across the country.
Private STI testing in Bangkok
Ovio can arrange private STI testing at a location that works for you.
Frequently Asked Questions
What is the earliest sign of HIV infection?
Usually a fever, around 2 to 4 weeks after infection, along with tiredness, aching muscles and a headache. Some people get no early sign at all.
What are the 1st symptoms of HIV?
A flu-like illness: fever, tiredness, muscle aches, headache, night sweats, sore throat, swollen glands, a rash, and sometimes mouth ulcers or diarrhoea. People rarely get just one of these.
Can HIV symptoms start after 1 week?
It can happen, but most people who get symptoms notice them 2 to 4 weeks after the exposure. Feeling ill a day or two afterwards is very unlikely to be HIV.
How long do early HIV symptoms last?
Anything from a few days to a few weeks; the median in the 2016 study was 8 days. The symptoms fade without treatment. The infection doesn't.
What does an HIV rash look like?
Small red or pink spots, flat or a little raised, mostly on the chest, back and face, and often not itchy. It usually comes with a fever and other symptoms. You can't diagnose HIV from a rash.
Can I have HIV and feel completely fine?
Yes, and for years. Some people skip the early illness entirely, and the chronic stage is often silent. If you've had a possible exposure, test regardless of how you feel.
Will an HIV test be positive when the symptoms start?
Not necessarily. Symptoms can start before some tests pick the virus up. Mention your symptoms to the doctor, who may add an RNA test to the 4th generation test and book a repeat later on.
Is HIV treatable?
Yes. There's no cure yet, but antiretroviral therapy keeps it under control. Someone diagnosed and treated early can expect a near-normal lifespan, and with an undetectable viral load they won't pass HIV on through sex.
Sources
- Symptoms of HIV (opens in a new tab)
- HIV and AIDS (opens in a new tab)
- HIV and AIDS fact sheet (opens in a new tab)
- HIV Testing (opens in a new tab)
- Signs or Symptoms of Acute HIV Infection in a Cohort Undergoing Community-Based Screening (Hoenigl M et al., Emerging Infectious Diseases 22(3):532–534) (opens in a new tab)
- Acute Human Immunodeficiency Virus Type 1 Disease as a Mononucleosis-Like Illness: Is the Diagnosis Too Restrictive? (Vanhems P et al., Clinical Infectious Diseases 24(5):965–970) (opens in a new tab)
- Morbidity and Mortality Weekly Report (MMWR), Recommendations and Reports 74(1) (opens in a new tab)
ABOUT THIS GUIDE
This guide gives general information and is not personal medical advice.
- Written by
- Kewalee Rujikajorn
- Published
