I have moderate sleep apnea and use the CPAP machine. Let me say that Banosser's post is a terrific analysis of why it is very important to address this condition. I had three sleep studies....the last one being done thru Brigham&Women's hospital in Boston. My doctor co-chairs the sleep study program with Harvard and Brigham. He prescribed the CPAP as had my previous doctor. It has taken a long time to get used to the mask.....however, I would not now go to sleep without it and take it wherever I am going to spend the night. It is a slight nuisance, at this point, but I have learned to adjust and get used to it. I I am not overweight, by any stretch, as many are who have apnea and I generally thought I got about 8 hours of cumulative sleep a night. However, I just felt awful....like I did not even sleep at all. Lack of concentration during the day, cranky, impatient etc. But, after a couple of years trying different masks and trying to pay attention to caffeine and liquor consumption, I was still feeling lousy. Anyway, I then had surgery on my severely deviated septum and yes I could breathe much better thru my nose....but It did not cure, but perhaps improved my sleep quality. My surgeon who had developed a procedure for Brigham to fix deviated septums without nose fracture and packing etc., said I had to give it time. Next, I worked with a nurse practitioner who wanted to put me on a strict sleep pattern schedule to be followed 7 days a week. I could not adhere to her regimen so we called it off. She did however, make me realize that I had to get control of anxiety and stress. She said I was taking it to bed with me and I had sort of a psychological insomia...her words. In essence. I would never really get into REM sleep because of apnea but also because I was not calm enough to get restful sleep. Next step. I saw a nurse practitioner trained in the field of psychiatry who was able to prescribe meds. Anyway, Iam now taking effexor for my anxiety, my nose has fully healed, and I use the mask religiously. I am doing much better. Sorry for the long winded response but there are many things that can alter sleep quality and I thought my experiences might be helpful. Best of luck!