Hi, I just started using the c- pap machine as I find it extremely suffocating to use the mask, but must use because sleep doctor has recommended it to keep my license. I have diabetes and fibromyalgia which I try to manage with medication like huminllin R-500 on an insulin pump and Ibuprofen , etc. I use Flonase to go to sleep and just before I put on the c-pap mask. I usually can get from 3-4 sleep with the mask on and always wake up with muscle pain & stiffness. However, whenever I take naps without the mask I wake up with neither muscle pain nor stiffness. My last sleep study with the mask that happened with muscle pain and stiffness. I had to go home and take a nap without the mask for 4 hours. The sleep study tech surmised that I didn t move too much and that was the reason for the pain. However, I have been reading that with fibromyalgia you can get alpha-delta sleep and muscle pain. what do you think?