insomnia
"I've only used it one night so far (over the fears of having sleep apnea, and waking when I can't breathe, a pill to keep me asleep just kind of scared me but walking around sleepier and sleepier each day, I caved.  True benefits I don't know yet, but I do know last night was the first night I slept over 8 hours STRAIGHT.  My Machine says I still had my sleep apnea events, but they seem about the same as normal."