^ Jump up to: a b c Cao, Xiao-Lan; Wang, Shi-Bin; Zhong, Bao-Liang; Zhang, Ling; Ungvari, Gabor S.; Ng, Chee H.; Li, Lu; Chiu, Helen F. K.; Lok, Grace K. I. (2017-02-24). "The prevalence of insomnia in the general population in China: A meta-analysis". PLoS ONE. 12 (2): e0170772. doi:10.1371/journal.pone.0170772. ISSN 1932-6203. PMC 5325204. PMID 28234940.
Narcolepsy is characterized by “sleep attacks” that occur during the day. This means that you will suddenly feel extremely tired and fall asleep without warning. The disorder can also cause sleep paralysis, which may make you physically unable to move right after waking up. Although narcolepsy may occur on its own, it is also associated with certain neurological disorders, such as multiple sclerosis.
Delayed sleep phase disorder (DSPD), inability to awaken and fall asleep at socially acceptable times but no problem with sleep maintenance, a disorder of circadian rhythms. Other such disorders are advanced sleep phase disorder (ASPD), non-24-hour sleep–wake disorder (non-24) in the sighted or in the blind, and irregular sleep wake rhythm, all much less common than DSPD, as well as the situational shift work sleep disorder.
Keep a pen and paper next to your bed. If you're often kept awake by racing thoughts and worries and you tend to make to-do lists in your head, keep a pen or pencil and a small pad of paper handy and write them down. As you put each item down on paper, imagine yourself setting aside that concern. (Again, use a book light; don't turn on the overhead or a bright bedside light to write.)