See this thread:
http://www.pprune.org/rumours-news/3...p-fatigue.html
I've asked the mods to merge this with that.
Sleep apnea is a serious problem for some people, often caused by weight issues, but not entirely. It can run in families, which implies that the general structure of the throat/windpipe/uvula can be better or worse for some.
There are night time breathing devices that provide positive air pressure via a nose or face mask to keep your windpipe from closing.
Sleep apnea occurs when the uvula in your throat relaxes and blocks your breathing, which essentially starts to suffocate you until your body reacts by snorting/snoring and partially jarring you awake. Not conducive for a good night's rest.