I use a CPAP machine as well and while my mouth is dry in the mornings I cannot say that I am particularly thirsty the rest of the time. Maybe medical advice would be better? Do you use any diuretics or take anything that would act as one?

Different type of drinking but sort of related. Just over a year ago I was drinking coffee through the day like it was going out of fashion and even eating roast coffee beans by the handful. In the evening I would drink at least a bottle of wine without it having the 'normal' effect. Then I was found to be severely anemic. Took iron tablets for a while and now just have 1 or 2 coffees a day and only indulge in my favourite tipples at weekend. It was my body needing the extra energy provided by both substances because my muscles could not get enough oxygen. Glad to say that for the past 10 or so months I have been fine.

Maybe your body is telling you something?

DtG