Waves,
The cough might be related to the cpap machine.

The air dries out my upper resp track and even my eyes I think.

Recently I was given a humidifier (50% of the sleep doc's patients use the humidifier. ) for the machine. I am trying different settings. My sis suggested that the moderately high setting might have caused the sore throat so last night I set the humidifier on the lowest setting. I woke up with dry (slightly cracking lips). . . . but hard to tell if the machine cased that at all because I fell asleep on the couch and was only in the bed with the cpap about three or four hours.

So for a proper experiment I need to keep track of
1. number of hours on the machine
2. setting of the the humidifier

I have to practice a bit.

No way to know yet.

M.