Any idea why a watery substance (mucus or saliva?) might be choking my wife while she is sleeping?...

...My wife snores and additionally wakes up many times with a sort of acid reflux almost vomiting in her mouth, but lately I have noticed something different as well.

While she sleeps I often read so I have to listen to the various sounds she makes. Lately it has gone beyond snoring to a sort of odd gargling or squishing sound, almost like the sound that would be made if you swirled water around in your mouth. It's a bit disturbing tbh.

I thought it might be some sort of post-nasal drip, but i'm not sure.

She sometimes sits up quickly and a saliva or near watery type fluid will drain out. Tonight she blew her nose twice and produced alot of very thin saliva (?) with maybe a slight pink coloration.

She has not smoked in a few years, but I sometimes do around her.

I feel really bad for her, but honestly between her snoring (especially when she is sleeping on her back), the gargling sounds, and her sometimes sitting bolt upright, it has become very annoying and made my slight insomnia even worse.

Any ideas what this could be and how it can be treated?

"This sounds like it could in fact be sleep apnea related snoring. This might explain the gurgling sounds. Try using very firm pillows and more pillows to keep her head elevated at night. There are also exercises she can do to help to tone the inner mouth. One of the reasons people snore is that the soft palate of the mouth becomes too floppy at night or the tongue loses muscle tone and lolls back against the windpipes. Whatever you do to help her stop snoring, it's worth. Snoring has been linked to a 67% increased risk of stroke."
(chosen answer)