A negative rapid flu test does not mean you do not have flu

It is impossible to tell for sure whether you have flu from symptoms alone.
Other viruses cause a similar illness, **flu can occur outside the usual
season**, and **people can have flu with respiratory symptoms and no fever at
all.**

So the question becomes which test, and they are not equivalent.

The four kinds

The first two rows are the ones worth reading twice. Five extra minutes
buys a meaningfully better answer, and both fit inside a single appointment.

Some RIDTs are FDA-approved for home use, including combined tests that
detect influenza A and B and SARS-CoV-2 in upper respiratory specimens.

Which way the error runs

You could still have flu, even though your rapid test result is negative.

That is the sentence to keep. A false positive sends someone home with
antivirals they did not need. A false negative sends home someone who has
influenza and has been told they do not — and if they are at higher risk, it
sends them home during the window in which antivirals still work.

CDC does not have specific guidance for the use of at-home flu tests, and
the advice it gives instead is about the decision rather than the device:

**People at higher risk of serious flu complications should seek medical
care promptly for flu-like symptoms, to determine if they need antiviral
medications.**

Promptly, and for care — not for a test result.

The symptoms

**Fever, cough, sore throat, runny or stuffy nose, body aches, headache,
chills, fatigue.** **Vomiting and diarrhoea are possible and more common in
children.**

All the laboratory tests need the same thing: **a swab of the inside of the
nose or the back of the throat.**

Source: Centers for Disease Control and Prevention.