My experience matches that of the other commenter, Karen Willoughby. I also have obstructive sleep apnea as well as MOTN insomnia (or sleep maintenance insomnia as I've seen it more commonly called). I sleep for four hours. I toss and turn during this time, but I go back to sleep relatively quickly. Once the four hour mark hits I'm suddenly awake and can immediately tell I won't be able to fall asleep again. So I lay in bed for a couple of hours and eventually - if I'm lucky - I'll have my second shift of sleep. If I'm unlucky I won't get back to sleep.

My sleep apnea is treated with CPAP, and it works just enough to barely get by. I've been through every single option with a sleep Dr. over the course of two years. Custom mouthpiece, nasal surgery, BIPAP trial, various medicines, in-lab sleep studies for central apnea, restless leg and periodic limb movement which were ruled out, none of it helped. Anyway, I couldn't help venting. I doubt anyone will read this. Peace.