Cold symptoms only at night

[Rupertgrintismyguiltypleasure]

The last 3 nights I’ve had cold symptoms, only at night, I’ve woken up perfectly fine. I do suffer from hay fever which I only developed 10 years ago when I was pregnant with dd. It started off just being June through to august but last year it started end of April through to September, so either my hay fever is rearing it’s ugly head sooner again or something else is going on.... anyone have an idea what I might be experiencing?
I do have hypothyroidism but generally I’ve only ever sometimes woken up with a runny nose and it usually disappears within an hour. But I’ve been like that since I was a kid.

Yes, I had same a few weeks ago. Very odd. It passed just like a normal cold would. Covid test was negative.

Have you been moving furniture about or anything. I get these symptoms when I’ve dusted and hoovered my bedroom, just that night, then I’m ok again, so I presume it’s dust allergy.