[doctor_eval]

I don’t think that’s the whole story, or even the most important part. My understanding is that blood pressure rises significantly during an apnea event and that over time this can cause all sorts of physical problems, especially blood vessel damage, leading to increased risk of heart attack and stroke.

I’d guess that lack of REM would cause symptoms like daytime drowsiness, but it’s the physiological effects that are gonna kill ya.

[pjerem]

Maybe but, correct me if I’m wrong, temporary high blood pressure isn’t really harmful.

My understanding is that bad sleep will induce chronic stress and chronic stress will induce high blood pressure.

So yes, bad sleep will dangerously increase blood pressure but it’s not a direct effect.

(That’s my interpretation, maybe it’s false)

[doctor_eval]

It’s physically harmful in the long term, can lead to serious vascular problems if left untreated.

In fact it turns out that REM sleep can sometimes compensate for apnea in some people, that is, the onset of REM can happen more quickly. Some people can get enough REM sleep even with apnea.

To be clear, ultimately all of these things can become problems, I’m just disputing that lost REM is the main health concern. It’s one concern, but AFAIK, in the long term venous damage is what will kill you.