Back in 2015 I was in hospital with pneumonia. It started as a sore throat, progressed into a chest infection, and ended up with me passing out due to not being able to breathe and then being taken to hospital in an ambulance with the blue lights flashing.
Whilst chatting to the doctor at the hospital he asked if I had used my CPAP machine prior to me passing out, to which I said that I hadn't; he said that it would've helped with my breathing and may have prevented me ending up in hospital. It seems obvious when you say it out loud, but at the time I just didn't think of it.
Since then, whenever I get the beginnings of a cough (as I have at the moment) I use my CPAP machine as much as I can; I find that it helps me breathe really well even when my nose is blocked.
I hugely resent having to use it every night to be able to sleep, but, when I am short of breath, putting it on and feeling that the first push of air is tremendously reassuring.