This new list of symptoms...

[storminabuttercup]

Sorry if this has been done but couldn't see a thread on it.
I've been thinking about this new list of symptoms, they are pretty varied and could be anything especially such as runny nose when they pollen is so high.
This may be a really stupid question but how do they know they are symptoms of Covid and not just that the person happens to have say the runs at the same time?

What new list?

They could be lots of things but that’s what the testing is for I guess.

Presumably a pcr test will tell you. As it does if you have a temperature

You don't know, which is why we test. But yiu do have some information on the prevalence of various infectious diseases in the local population, so can estimate relative probabilities that way.

Loads of people are recording their day to day health on the Zoe app. They’re got a stack of data they can then use to analyse what symptoms people are getting with covid.

I guess I get that it's similar to knowing what the three 'main' symptoms are. I was just interested as there's now so many more.
The Zoe app thing makes sense.
I can't find anything on the website so say we should be testing with the new list though

This is the list