Can you take a LFT or PCR test at any point that you are Ill?

[JasonMomoasgirlfriend]

Cause I seem to remember the PCR Instructions were to do it within 4 days of symptoms but I wondered if that's out the window now the isolation rules changed.

Does a positive show the whole time you are ill or does it have to be in the 4 day window? And what about LFTs?

Basically I have been ill for a week weeks and I have done a few LFTs but all negative so far however I haven't been religious in doing them. I assume a cold or pregnancy related issue but today I'm coughing/wheezy a lot and my lungs just don't feel right.
So wondering if I'm too late for a PCR anyway? I don't have any LFTs left in the house either I don't think

If you have symptoms you should do a PCR, not LFT as they aren't sensitive enough to rule out covid and give a lot of false negatives.

Think its within 8 days of symptoms but you can still test positive for a few months afterwards too.

Honestly, people rely too much on LFTs, if you have symptoms go and get a proper test. I work for 119 and the stupidity around LFT testing is really making me hope these tests are stopped or become chargable asap.

Well in Scotland they are telling us to do them every few days..
I haven't actually because I am WFH and rarely out anywhere at all.
I will order a PCR just to check. I found a spare LFT and it's negative though.

They are advised twice a week to catch some asymptomatic cases (they will pick up 50-60% of them if you're lucky). If you have symptoms it's a PCR you need.

An LTF doesn’t test for the virus, it’s a test to identify an immune response to the virus. So you’ll only get a positive ltf is your immune system is stimulated by covid hence why it’s most useful for picking up asymptomatic cases.

A PCR test check for the virus itself, so if you have symptoms then you should def got for one.

If you have symptoms you have a pcr not lft.
You can test regularly with an lft but NOT if you have symptoms.

@yellow85 why would asymptomatic Covid cause an immune response but not symptomatic Covid? How would your body know to produce a response (ie symptoms) if it's not an immune response?

Love to understand more about the science here.

So is it that you've felt unwell but not with one of the three testable symptoms, until now when you've got a cough?
I believe you're supposed to get the PCR within five days of symptoms starting, but in your case would that be the cough starting? I don't know. People who've had Covid aren't supposed to do a test for 90 days so I'm assuming it would still show up on a test.

[quote Whattheflecker]@yellow85 why would asymptomatic Covid cause an immune response but not symptomatic Covid? How would your body know to produce a response (ie symptoms) if it's not an immune response?

Love to understand more about the science here.[/quote]
Me too although your immune system may produce different symptoms. The “three symptoms” for a PCR test are not the only ones and they’re not the main ones for the newer variant either.

@Iggly

Symptomatic does as well, but the likely hood is you either get symptoms before your body produced enough protein to give positive ltf, or if you’ve been in contact with someone, you’d get a PCR beforehand too.

That’s why they are called antigen tests, because they’re actually testing for early antibodies.

It’s bloody magic really 🤣

To be fair, everyone I know who's had symptomatic covid have tested positive on LFT as well as on pcr (I'm not suggesting you don't get a pcr b the way)

@hellcatspangle

To be fair, everyone I know who's had symptomatic covid have tested positive on LFT as well as on pcr (I'm not suggesting you don't get a pcr b the way)

Most people would. It’s more of a timing thing really, as we’ve had loads of cases here with negative LTFs but positive PCR. But it’s because they were really early tests due to contact rather than symptoms.

Even if you did have positive PCR, the like this is any subsequent LTFs would start to turn positive too.

@hellcatspangle

To be fair, everyone I know who's had symptomatic covid have tested positive on LFT as well as on pcr (I'm not suggesting you don't get a pcr b the way)

That's the issue with LFT. They are more accurate if you have symptoms and will pick up maybe 50-60% of cases if you have no symptoms