Editing Sleep disorder (section)

== Epidemiology ==
=== Children and young adults ===
According to one meta-analysis of sleep disorders in children, [[confusional arousals]] and [[sleepwalking]] are the two most common sleep disorders among children.<ref name=":1">{{cite journal | vauthors = Carter KA, Hathaway NE, Lettieri CF | title = Common sleep disorders in children | journal = American Family Physician | volume = 89 | issue = 5 | pages = 368–377 | date = March 2014 | pmid = 24695508 | url = http://www.aafp.org/afp/2014/0301/p368.html }}</ref> An estimated 17.3% of kids between 3 and 13 years old experience confusional arousals.<ref name=":1" /> About 17% of children sleepwalk, with the disorder being more common among boys than girls,<ref name=":1" /> the peak ages of sleepwalking are from 8 to 12 years old.<ref name=":1" />

A different systematic review offers a high range of prevalence rates of [[Bruxism|sleep bruxism]] for children. Parasomnias like sleepwalking and talking typically occur during the first part of an individual's sleep cycle, the first slow wave of sleep <ref>{{cite journal | vauthors = Carter KA, Hathaway NE, Lettieri CF | title = Common sleep disorders in children | journal = American Family Physician | volume = 89 | issue = 5 | pages = 368–377 | date = March 2014 | pmid = 24695508 | url = https://pubmed.ncbi.nlm.nih.gov/24695508/ }}</ref> During the first slow wave of sleep period of the sleep cycle the mind and body slow down causing one to feel drowsy and relaxed. At this stage it is the easiest to wake up, therefore many children do not remember what happened during this time.

Nightmares are also considered a parasomnia among children, who typically remember what took place during the nightmare. However, nightmares only occur during the last stage of sleep - [[Rapid eye movement sleep|Rapid Eye Movement (REM)]] sleep. REM is the deepest stage of sleep, it is named for the host of neurological and physiological responses an individual can display during this period of the sleep cycle which are similar to being awake'''.<ref>{{cite book| vauthors = Patel AK, Reddy V, Shumway KR, Araujo AF | chapter = Physiology, Sleep Stages |date=2021| chapter-url = http://www.ncbi.nlm.nih.gov/books/NBK526132/| title = StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=30252388|access-date=2021-09-19}}</ref>'''

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 [[Bruxism|bruxist]] prevalence as age increased, as well as a higher prevalence among boys than girls.<ref>{{cite journal | vauthors = Machado E, Dal-Fabbro C, Cunali PA, Kaizer OB | title = Prevalence of sleep bruxism in children: a systematic review | journal = Dental Press Journal of Orthodontics | volume = 19 | issue = 6 | pages = 54–61 | date = 2014 | pmid = 25628080 | pmc = 4347411 | doi = 10.1590/2176-9451.19.6.054-061.oar }}</ref>

Another systematic review noted 7-16% of young adults have [[delayed sleep phase disorder]]. This disorder reaches peak prevalence when people are in their 20s.<ref name=":1" />  Between 20 and 26% of adolescents report a [[sleep onset latency]] of greater than 30 minutes. Also, 7-36% have difficulty initiating sleep.<ref name=":4">{{cite journal | vauthors = Gradisar M, Gardner G, Dohnt H | title = Recent worldwide sleep patterns and problems during adolescence: a review and meta-analysis of age, region, and sleep | journal = Sleep Medicine | volume = 12 | issue = 2 | pages = 110–118 | date = February 2011 | pmid = 21257344 | doi = 10.1016/j.sleep.2010.11.008 }}</ref>  Asian teens tend to have a higher prevalence of all of these adverse sleep outcomes—than their North American and European counterparts.<ref name=":4" />

By adulthood, parasomnias can normally be resolved due to a person's growth; however, 4% of people have recurring symptoms.

=== Effects of Untreated Sleep Disorders ===
Children and young adults who do not get enough sleep due to sleep disorders also have many other health problems such as obesity and physical problems where it could interfere with everyday life.<ref>{{cite journal | vauthors = Wheaton AG, Jones SE, Cooper AC, Croft JB | title = Short Sleep Duration Among Middle School and High School Students - United States, 2015 | language = en-us | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 67 | issue = 3 | pages = 85–90 | date = January 2018 | pmid = 29370154 | pmc = 5812312 | doi = 10.15585/mmwr.mm6703a1 }}</ref> It is recommended that children and young adults stick to the hours of sleep recommended by the CDC, as it helps increase mental health, physical health, and more.<ref>{{cite journal | vauthors = Paruthi S, Brooks LJ, D'Ambrosio C, Hall WA, Kotagal S, Lloyd RM, Malow BA, Maski K, Nichols C, Quan SF, Rosen CL, Troester MM, Wise MS | display-authors = 6 | title = Consensus Statement of the American Academy of Sleep Medicine on the Recommended Amount of Sleep for Healthy Children: Methodology and Discussion | journal = Journal of Clinical Sleep Medicine | volume = 12 | issue = 11 | pages = 1549–1561 | date = November 2016 | pmid = 27707447 | pmc = 5078711 | doi = 10.5664/jcsm.6288 }}</ref>

=== Insomnia ===
[[Insomnia]] is a prevalent form of sleep deprivation. Individuals with insomnia may have problems falling asleep, staying asleep, or a combination of both resulting in hyposomnia - i.e. insufficient quantity and poor quality of sleep.<ref name="Zeitlhofer et al. 1993">{{cite journal | vauthors = Zeitlhofer J, Tribl G, Saletu B | title = [Sleep disorders in neurology: hyposomnia] | journal = Wiener Klinische Wochenschrift | volume = 105 | issue = 2 | pages = 37–41 | year = 1993 | pmid = 8442353 }}</ref>

Combining results from 17 studies on insomnia in China, a pooled prevalence of 15.0% is reported for the country.<ref name=":5">{{cite journal | vauthors = Cao XL, Wang SB, Zhong BL, Zhang L, Ungvari GS, Ng CH, Li L, Chiu HF, Lok GK, Lu JP, Jia FJ, Xiang YT | display-authors = 6 | title = The prevalence of insomnia in the general population in China: A meta-analysis | journal = PLOS ONE | volume = 12 | issue = 2 | pages = e0170772 | date = 2017-02-24 | pmid = 28234940 | pmc = 5325204 | doi = 10.1371/journal.pone.0170772 | doi-access = free | bibcode = 2017PLoSO..1270772C }}</ref>  This result is consistent among other [[East Asia]]n countries; however, this is considerably lower than a series of [[Western world|Western countries]] (50.5% in Poland, 37.2% in France and Italy, 27.1% in USA).<ref name=":5" /> Men and women residing in China experience insomnia at similar rates.<ref name=":5" />

A separate meta-analysis focusing on this sleeping disorder in the elderly mentions that those with more than one physical or psychiatric malady experience it at a 60% higher rate than those with one condition or less. It also notes a higher prevalence of insomnia in women over the age of 50 than their male counterparts.<ref>{{cite journal | vauthors = Rodriguez JC, Dzierzewski JM, Alessi CA | title = Sleep problems in the elderly | journal = The Medical Clinics of North America | volume = 99 | issue = 2 | pages = 431–439 | date = March 2015 | pmid = 25700593 | pmc = 4406253 | doi = 10.1016/j.mcna.2014.11.013 }}</ref>

A study that was resulted from a collaboration between [[Massachusetts General Hospital]] and [[Merck & Co.|Merck]] describes the development of an [[algorithm]] to identify patients with sleep disorders using electronic medical records. The algorithm that incorporated a combination of structured and unstructured variables identified more than 36,000 individuals with physician-documented insomnia.<ref>{{cite journal | vauthors = Kartoun U, Aggarwal R, Beam AL, Pai JK, Chatterjee AK, Fitzgerald TP, Kohane IS, Shaw SY | display-authors = 6 | title = Development of an Algorithm to Identify Patients with Physician-Documented Insomnia | journal = Scientific Reports | volume = 8 | issue = 1 | pages = 7862 | date = May 2018 | pmid = 29777125 | pmc = 5959894 | doi = 10.1038/s41598-018-25312-z | bibcode = 2018NatSR...8.7862K }}</ref>

Insomnia can start off at the basic level but about 40% of people who struggle with insomnia have worse symptoms.<ref name="Pavlova 292–299">{{cite journal | vauthors = K Pavlova M, Latreille V | title = Sleep Disorders | language = English | journal = The American Journal of Medicine | volume = 132 | issue = 3 | pages = 292–299 | date = March 2019 | pmid = 30292731 | doi = 10.1016/j.amjmed.2018.09.021 | s2cid = 52935007 }}</ref> There are treatments that can help with insomnia and that includes medication, planning out a sleep schedule, limiting oneself from caffeine intake, and cognitive behavioral therapy.<ref name="Pavlova 292–299" />

=== Obstructive sleep apnea ===
[[Obstructive sleep apnea]] (OSA) affects around 4% of men and 2% of women in the United States.<ref name=":2">{{cite journal | vauthors = Mirrakhimov AE, Sooronbaev T, Mirrakhimov EM | title = Prevalence of obstructive sleep apnea in Asian adults: a systematic review of the literature | journal = BMC Pulmonary Medicine | volume = 13 | pages = 10 | date = February 2013 | pmid = 23433391 | pmc = 3585751 | doi = 10.1186/1471-2466-13-10 | doi-access = free }}</ref> In general, this disorder is more prevalent among men. However, this difference tends to diminish with age. Women experience the highest risk for OSA during pregnancy,<ref name=":0">{{cite journal | vauthors = Wimms A, Woehrle H, Ketheeswaran S, Ramanan D, Armitstead J | title = Obstructive Sleep Apnea in Women: Specific Issues and Interventions | journal = BioMed Research International | volume = 2016 | pages = 1764837 | date = 2016 | pmid = 27699167 | pmc = 5028797 | doi = 10.1155/2016/1764837 | doi-access = free }}</ref> and tend to report experiencing [[Depression (mood)|depression]] and [[insomnia]] in conjunction with obstructive sleep apnea.<ref name=":3">{{cite journal | vauthors = Valipour A | title = Gender-related differences in the obstructive sleep apnea syndrome | journal = Pneumologie | volume = 66 | issue = 10 | pages = 584–588 | date = October 2012 | pmid = 22987326 | doi = 10.1055/s-0032-1325664 | doi-access = free }}</ref>

In a meta-analysis of the various Asian countries, India and China present the highest prevalence of the disorder. Specifically, about 13.7% of the Indian population and 7% of Hong Kong's population is estimated to have OSA. The two groups in the study experience daytime OSA symptoms such as difficulties concentrating, mood swings, or high blood pressure,<ref>{{Cite web|url=https://www.mayoclinic.org/diseases-conditions/obstructive-sleep-apnea/symptoms-causes/syc-20352090|title=Obstructive sleep apnea – Symptoms and causes – Mayo Clinic|website=www.mayoclinic.org|access-date=2017-11-27}}</ref> at similar rates (prevalence of 3.5% and 3.57%, respectively).<ref name=":2" />

=== Obesity and Sleep Apnea ===
The worldwide incidence of obstructive sleep apnea (OSA) is on the rise, largely due to the increasing prevalence of obesity in society. In individuals who are obese, excess fat deposits in the upper respiratory tract can lead to breathing difficulties during sleep, giving rise to OSA. There is a strong connection between obesity and OSA, making it essential to screen obese individuals for OSA and related disorders. Moreover, both obesity and OSA patients are at higher risk of developing metabolic syndrome. Implementing dietary control in obese individuals can have a positive impact on sleep problems and can help alleviate associated issues such as depression, anxiety, and insomnia.<ref>{{Cite journal |last=Owen |first=Lauren |last2=Corfe |first2=Bernard |date=November 2017 |title=The role of diet and nutrition on mental health and wellbeing |url=https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/role-of-diet-and-nutrition-on-mental-health-and-wellbeing/372284768DB78DB02EB199E277AABF79 |journal=Proceedings of the Nutrition Society |language=en |volume=76 |issue=4 |pages=425–426 |doi=10.1017/S0029665117001057 |issn=0029-6651}}</ref> [[Sleep and weight|Obesity]] can influence the disturbance in sleep patterns resulting in OSA. <ref>{{cite journal | vauthors = Lee JH, Cho J | title = Sleep and Obesity | journal = Sleep Medicine Clinics | volume = 17 | issue = 1 | pages = 111–116 | date = March 2022 | pmid = 35216758 | doi = 10.1016/j.jsmc.2021.10.009 | s2cid = 245696606 }}</ref> Obesity is a risk factor for OSA because it can affect the upper respiratory system by accumulating fat deposition around the muscles surrounding the lungs. Additionally, OSA can irritate the obesity by prolonging sleepiness throughout the day leading to reduces physical activity and an inactive lifestyle.<ref name=":24" /> 

=== Sleep paralysis ===
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%).<ref>{{cite journal | vauthors = Sharpless BA, Barber JP | title = Lifetime prevalence rates of sleep paralysis: a systematic review | journal = Sleep Medicine Reviews | volume = 15 | issue = 5 | pages = 311–315 | date = October 2011 | pmid = 21571556 | pmc = 3156892 | doi = 10.1016/j.smrv.2011.01.007 }}</ref>

=== Restless legs syndrome ===
According to one meta-analysis, the average prevalence rate for North America,             and Western Europe is estimated to be 14.5±8.0%. Specifically in the United States, the prevalence of [[restless legs syndrome]] is estimated to be between 5% and 15.7% when using strict diagnostic criteria. RLS is over 35% more prevalent in American women than their male counterparts.<ref>{{cite journal | vauthors = Innes KE, Selfe TK, Agarwal P | title = Prevalence of restless legs syndrome in North American and Western European populations: a systematic review | journal = Sleep Medicine | volume = 12 | issue = 7 | pages = 623–634 | date = August 2011 | pmid = 21752711 | pmc = 4634567 | doi = 10.1016/j.sleep.2010.12.018 }}</ref> Restless Leg Syndrome (RLS) is a sensorimotor disorder characterized by discomfort in the lower limbs. Typically, symptoms worsen in the evening, improve with movement, and exacerbate when at rest.<ref>{{Cite journal |last1=Kocabicak |first1=Ersoy |last2=Terzi |first2=Murat |last3=Akpinar |first3=Kursad |last4=Paksoy |first4=Kemal |last5=Cebeci |first5=Ibrahim |last6=Iyigun |first6=Omer |date=2014 |title=Restless Leg Syndrome and Sleep Quality in Lumbar Radiculopathy Patients |journal=Behavioural Neurology |language=en |volume=2014 |pages=1–5 |doi=10.1155/2014/245358 |doi-access=free |pmid=25110396 |pmc=4109372 |issn=0953-4180}}</ref>