Lew, yes I've got a borderline case of sleep apnea, they did the test, yada, yada, plugged me into the Darth Vader air compressor, what a fight. Went back several times for different masks, full face, nose only, the best I did was 2 hours. The last horrible episode had me wake up with about 50 psi inside me and ready to hurl..very far. I guess somehow it was filling my gastro intestinal tract for quite a while. Anyway, burped and pharted for an eternity. Next morning the machine went back. There is another alternative they advertise, it's a dental fitting that prevnets snoring, advertised a lot on the radio. Here's the link: http://torontodentalcare.ca/dental_services/snoring.html