A systematic review states 7.6% of the general population experiences sleep paralysis at least once in their lifetime. Its prevalence among men is 15.9% while 18.9% of women experience it. When considering specific populations, 28.3% of students and 31.9% of psychiatric patients have experienced this phenomenon at least once in their lifetime. Of those psychiatric patients, 34.6% have panic disorder. Sleep paralysis in students is slightly more prevalent for those of Asian descent (39.9%) than other ethnicities (Hispanic: 34.5%, African descent: 31.4%, Caucasian 30.8%).[67]
^ Tranah, Gregory J.; Blackwell, Terri; Stone, Katie L.; Ancoli‐Israel, Sonia; Paudel, Misti L.; Ensrud, Kristine E.; Cauley, Jane A.; Redline, Susan; Hillier, Teresa A. (2011). "Circadian activity rhythms and risk of incident dementia and mild cognitive impairment in older women". Annals of Neurology. 70 (5): 722–732. doi:10.1002/ana.22468. ISSN 1531-8249.
According to one meta-analysis, the two most prevalent sleep disorders among children are confusional arousals and sleep walking.[57] An estimated 17.3% of kids between 3 and 13 years old experience confusional arousals.[57] About 17% of children sleep walk, with the disorder being more common among boys than girls.[57] The peak ages of sleep walking are from 8 to 12 years old.[57] A different systematic review offers a high range of prevalence rates of sleep bruxism for children. Between 15.29 and 38.6% of preschoolers grind their teeth at least one night a week. All but one of the included studies reports decreasing bruxist prevalence as age increased as well as a higher prevalence among boys than girls.[58]

In addressing sleep disorders and possible solutions, there is often a lot of buzz surrounding melatonin. Research suggests that melatonin is useful in helping people to fall asleep faster (decreased sleep latency), to stay asleep longer, and to experience improved sleep quality. In order to test this, a study was conducted that compared subjects that had taken Melatonin to subjects that had taken a placebo pill in subjects with primary sleep disorders. Researchers assessed sleep onset latency, total minutes slept, and overall sleep quality in the Melatonin and placebo groups to note the differences. In the end, researchers found that melatonin decreased sleep onset latency, increased total sleep time, and improved quality of sleep significantly more than the placebo group.[49][50]
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.[4]
Get back to sleep when you wake up at night. Whether you have a sleep disorder or not, it’s normal to wake briefly during the night. If you’re having trouble getting back to sleep, try focusing on your breathing, meditating, or practicing another relaxation technique. Make a note of anything that’s worrying you and resolve to postpone worrying about it until the next day when it will be easier to resolve.
Sort of a milder cousin of sleep apnea, UARS occurs when some type of resistance slows or blocks air in the nasal passages. The most common causes are mild nasal congestion or a tongue position during sleep that blocks breathing. Because the resistance makes it harder work simply to breathe, your body is half-waking up over and over again during the night, so you don't feel refreshed in the morning.
^ Keckeis, Marietta; Lattova, Zuzana; Maurovich-Horvat, Eszter; Beitinger, Pierre A.; Birkmann, Steffen; Lauer, Christoph J.; Wetter, Thomas C.; Wilde-Frenz, Johanna; Pollmächer, Thomas (2010). Finkelstein, David (ed.). "Impaired Glucose Tolerance in Sleep Disorders". PLoS ONE. 5 (3): e9444. doi:10.1371/journal.pone.0009444. PMC 2830474. PMID 20209158.
Sleep disturbances have been also observed in Alzheimer's disease (AD), affecting about 45% of its population.[22][24][26] Moreover, when it is based on caregiver reports this percentage is even higher, about 70%.[28] As well as in PD population, insomnia and hypersomnia are frequently recognized in AD patients, which have been associated with accumulation of Beta-amyloid, circadian rhythm sleep disorders (CRSD) and melatonin alteration.[22][24][28] Additionally, changes in sleep architecture are observed in AD too.[22][24][26] Even though with ageing the sleep architecture seems to change naturally, in AD patients it is aggravated. SWS is potentially decreased (sometimes totally absent), spindles and the time spent in REM sleep are also reduced, while its latency is increased.[28] The poorly sleep onset in AD has been also associated with dream-related hallucination, increased restlessness, wandering and agitation, that seem to be related with sundowning - a typical chronological phenomenon presented in the disease.[24][28]
As suggested by its name, PLMD is an involuntary movement disorder. (An older name, nocturnal myoclonus , is rarely used anymore.) People with this problem experience sudden, involuntary leg movements during the night, such as kicking or jerking. The difference between this and restless leg syndrome is that, unless the kicking wakes you up, you don't know you're doing it. You don't experience the tingling and discomfort that leads you to consciously move your legs, as with restless leg syndrome. At least 80 percent of people with restless leg syndrome have PLMD, but the reverse isn't true.
If your snoring is loud and uneven, erupts in snorts, or you sound like you're catching your breath or there are gaps in your breathing, these are signs of obstructive sleep apnea, the most severe type of sleep-disordered breathing. People with sleep apnea stop breathing repeatedly during their sleep because of a blockage in the mouth or throat, most commonly the soft tissues in the back of the throat, which collapse and close off.