A timeline after a possible exposure

Here’s what can happen in the weeks after HIV enters the body, and what you can do at each stage.

  • Days 0 to 3: No symptoms and no test can detect anything yet. This is when PEP (post-exposure prophylaxis) can help. It must start within 72 hours.
  • Weeks 1 to 2: Early symptoms, if they happen, usually haven’t started yet. A NAT (nucleic acid test) can start to detect HIV from about day 10.
  • Weeks 2 to 4: If early symptoms happen, this is usually when they start. A lab antigen/antibody test can detect HIV from about day 18.
  • The weeks after: Early symptoms usually last from a few days to several weeks, then go away on their own. HIV doesn’t go away with them.
  • Day 33: A negative NAT is conclusive.
  • Day 45: A negative lab antigen/antibody test is conclusive.
  • Day 90: A negative result on any test, including rapid tests and home tests, is conclusive.

What early symptoms can look like

This early stage is called acute HIV infection. According to HIV.gov, symptoms can include:

  • fever and chills
  • rash
  • night sweats
  • muscle aches
  • sore throat
  • tiredness
  • swollen lymph nodes (glands)
  • mouth ulcers

It looks a lot like flu, and that’s the problem. Some people get none of these at all.

Why symptoms can’t diagnose HIV

There are three reasons not to read too much into how you feel.

Many people with HIV have no early symptoms. Feeling well doesn’t rule HIV out.

These symptoms can be caused by many other illnesses. A cold, flu or another virus can look exactly the same.

There’s no pattern that settles it. No combination of symptoms, and no particular rash or sore throat, can confirm or rule out HIV. As HIV.gov puts it, the only way to know for sure is to get tested.

If you do get symptoms after a possible exposure, don’t wait them out. See a clinician, say you may have been exposed to HIV, and ask for a test that can detect early infection, such as a NAT or a lab antigen/antibody test.

When worry causes symptoms too

Anxiety is physical as well as mental. The NHS lists symptoms such as a more noticeable or unusual heartbeat, stomach problems, feeling tense, getting tired easily, feeling dizzy or lightheaded, and trouble sleeping.

After an exposure, it’s easy to notice every ache and wonder if it’s HIV. Checking your body over and over tends to make the worry worse, not better. The way to settle the question is the right test at the right time. If the worry is taking over, see coping with HIV anxiety.

Put your symptoms next to the actual risk

How likely HIV is depends far more on what happened than on how you feel now. For most exposures the chance is low. One act of oral sex with a partner who has HIV and isn’t on treatment comes to 0.01% (about 1 in 10,000). For a woman having vaginal sex once without a condom with a man of unknown status in the US, it’s 0.00014% (about 1 in 730,000). The calculator can give you an estimate for your situation.

What to do now

  1. If the exposure was in the last 72 hours, ask about PEP today. Don’t wait to see whether symptoms appear.
  2. If you have symptoms now, see a clinician and ask for a NAT or a lab antigen/antibody test.
  3. If you have no symptoms, that doesn’t rule anything out. Plan a test based on the date of the exposure. See HIV test accuracy by week.
  4. Retest after the window period if your first test was inside it.
  5. Get help with the worry if it’s affecting your sleep, work or relationships.

A negative test after the window period settles it. If you tested negative after the window for that test, and haven’t had another exposure since, you don’t have HIV from that exposure, whatever symptoms you notice. If symptoms carry on, see a doctor, as something else may be causing them.