What are the 5 levels of sleep?

From what I understand, in the typical person the amount of cortisol in the blood undergoes a diurnal variation with the level peaking in the early morning and reaching its lowest level around midnight to 2AM. What if you're on an atypical sleep schedule...

Hello, What do you think about the use of luminotherapy lamps to regulate energy levels through the day for a better sleep? I don't always have the time to  go out during the day and moreover, I live in a country where the climate is not friendly......

Last night I took a sleep study, and the doctor called me back and said I have mild sleep apnea, and he was more concerned with my low oxygen levels, so he is going to do a test from my home when I sleep to check my oxygen with a cpap machine while I...

I recently was diagnosed with Sleep Apnea and tried a CPAP at a sleep study. It apparently worked for me. Without CPAP, I stopped breathing on average of 45-46 times. With CPAP, only 5 times during the night. I slept 87% of the night with the CPAP on...

I have been suffering from something for a very long time now......first happened when I was about 20 I am 29 now......I took some pain medicine and when I went to bed that night I was woken up by some kind of jolt or I was gasping for air I could never...

I've been getting less than 4 hours of sleep the last 5 days since I'm in the middle of relocating into another apartment in L.A., and you can imagine the kind of stress that ...show more

Whenever I wake up early, I can't do anything after work. I just sit in my bed, I wish I could do sports but I'm exhausted. I can't set up a routine for myself. My health is perfect (as far as can be seen), I'm currently not depressed and I am only ...

The ideal range of CO2 levels would be 335 ppm. Not the realistic solution for climate change, but since the global warming has been caused mostly by the human, it may be interesting to try thinking about.

from 8 hours to 5 1/2