COVID symptoms are no joke, and those who manifest them should be very careful. PCR tests are common for detecting those who suffer from the coronavirus, but even if they reveal a negative result, opening the champagne just yet is not an option. The Guardian reveals the claim of health officials saying that those who manifest COVID symptoms should consider self-isolation even though a PCR test comes back negative.
The claim comes after some cases of people testing positive using lateral flow tests were tested negative with PCR tests afterward.
South-west England is the region in question
The discrepancies were reported for people from the Southwest part of England last week. The UK Health Security Agency (UKHSA), which is formerly known as the Public Health England, expressed astonishment.

Susan Hopkins, who is the chief medical adviser at the UKHSA, declared as quoted by The Guardian:
We have been made aware of some areas reporting positive LFD [lateral flow device] test results with subsequent negative PCR tests and we are looking into the cause.
If you get a positive LFD test, it’s important to make sure that you then get a follow-up PCR test to confirm you have Covid-19. If you have symptoms of Covid-19, self-isolate and take a PCR test. With any test, it is important to carefully read and follow the instructions for use on the test kit so as to avoid any incorrect readings.
The classical COVID symptoms are pretty much known by everybody until now: cough, fever, headaches, loss of taste or smell, sore throat, aches, and so on.