Prior to my bypass which was on 9/04/14 I was using a CPAP mask for several months and adjusted to it quite easily, and tolerated it for the entire night. However, after my bypass I cannot tolerate it at all. I have tried wearing it numerous times but wake up horribly nauseated. The nausea goes away when I turn the CPAP machine off. What is going on? My sleep apnea couldn't have disappeared this fast....or could it?

Let me know if anyone else is having or had this issue.

Maybe the pressure needs to be adjusted. I would talk to the sleep clinic they may have suggestions perhaps a different type of mask.

I am also having an issue with my CPAP. Have been using it for years with no problems until after bypass surgery. My problem is dry mouth. I have a RAMP on my machine, the pressure is lower for about 45 minutes, then it automatically goes up to full pressure. I wake up about an hour later and am choking cause my mouth is so dry. I turned up the humidifier to the highest setting with no relief. I had the machine checked and it is working fine. They could tell by the diagnostics on the SD card I was not mouth breathing at night. They cannot adjust the pressure without a doctors order. So now I have to see my regular doctor, hoping they can do another sleep study to see if I even still need the machine.

If you have lost 50 or more pounds, you're supposed to get another sleep study done. You might need a lower air pressure setting, so see your sleep doctor soon.