Editing Circadian rhythm (section)

==== Disruption ====
{{Further|Circadian rhythm sleep disorder}}
Disruption to rhythms usually has a negative effect. Many travelers have experienced the condition known as [[jet lag]], with its associated symptoms of [[fatigue (physical)|fatigue]], [[disorientation]] and [[insomnia]].<ref>{{Cite web |title=The science of jet lag |url=https://www.timeshifter.com/jet-lag/the-science-of-jet-lag |access-date=2023-01-03 |website=Timeshifter |language=en}}</ref>

A number of other disorders, such as [[bipolar disorder]], [[Major depressive disorder|depression]], and some [[sleep disorder]]s such as [[delayed sleep phase disorder]] (DSPD), are associated with irregular or pathological functioning of circadian rhythms.<ref>{{cite journal | vauthors = Gold AK, Kinrys G | title = Treating Circadian Rhythm Disruption in Bipolar Disorder | journal = Current Psychiatry Reports | volume = 21 | issue = 3 | pages = 14 | date = March 2019 | pmid = 30826893 | pmc = 6812517 | doi = 10.1007/s11920-019-1001-8 }}</ref><ref>{{cite journal | vauthors = Zhu L, Zee PC | title = Circadian rhythm sleep disorders | journal = Neurologic Clinics | volume = 30 | issue = 4 | pages = 1167–1191 | date = November 2012 | pmid = 23099133 | pmc = 3523094 | doi = 10.1016/j.ncl.2012.08.011 }}</ref><ref>{{Cite journal |last1=Crouse |first1=Jacob J |last2=Carpenter |first2=Joanne S |last3=Song |first3=Yun Ju C |last4=Hockey |first4=Samuel J |last5=Naismith |first5=Sharon L |last6=Grunstein |first6=Ronald R |last7=Scott |first7=Elizabeth M |last8=Merikangas |first8=Kathleen R |last9=Scott |first9=Jan |last10=Hickie |first10=Ian B |date=September 2021 |title=Circadian rhythm sleep–wake disturbances and depression in young people: implications for prevention and early intervention |url=https://linkinghub.elsevier.com/retrieve/pii/S2215036621000341 |journal=The Lancet Psychiatry |language=en |volume=8 |issue=9 |pages=813–823 |doi=10.1016/S2215-0366(21)00034-1|pmid=34419186 }}</ref><ref>{{Cite journal |last1=Scott |first1=Jan |last2=Etain |first2=Bruno |last3=Miklowitz |first3=David |last4=Crouse |first4=Jacob J. |last5=Carpenter |first5=Joanne |last6=Marwaha |first6=Steven |last7=Smith |first7=Daniel |last8=Merikangas |first8=Kathleen |last9=Hickie |first9=Ian |date=April 2022 |title=A systematic review and meta-analysis of sleep and circadian rhythms disturbances in individuals at high-risk of developing or with early onset of bipolar disorders |journal=Neuroscience & Biobehavioral Reviews |language=en |volume=135 |pages=104585 |doi=10.1016/j.neubiorev.2022.104585 |pmc=8957543 |pmid=35182537}}</ref>

Disruption to rhythms in the longer term is believed to have significant adverse health consequences for peripheral organs outside the brain, in particular in the development or exacerbation of cardiovascular disease.<ref name="Zelinski2014">{{cite journal | vauthors = Zelinski EL, Deibel SH, McDonald RJ | title = The trouble with circadian clock dysfunction: multiple deleterious effects on the brain and body | journal = Neuroscience and Biobehavioral Reviews | volume = 40 | issue = 40 | pages = 80–101 | date = March 2014 | pmid = 24468109 | doi = 10.1016/j.neubiorev.2014.01.007 | s2cid = 6809964 }}</ref><ref>Oritz-Tuldela E, Martinez-Nicolas A, Diaz-Mardomingo C, Garcia-Herranz S, Pereda-Perez I, Valencia A, Peraita H, Venero C, Madrid J, Rol M. 2014. The Characterization of Biological Rhythms in Mild Cognitive Impairment. BioMed Research International.</ref>

Studies have shown that maintaining normal sleep and circadian rhythms is important for many aspects of brain and health.<ref name="Zelinski2014" /> A number of studies have also indicated that a [[power-nap]], a short period of sleep during the day, can reduce stress and may improve productivity without any measurable effect on normal circadian rhythms.<ref>{{cite journal | vauthors = Hershner SD, Chervin RD | title = Causes and consequences of sleepiness among college students | journal = Nature and Science of Sleep | volume = 6 | pages = 73–84 | date = 2014-06-23 | pmid = 25018659 | pmc = 4075951 | doi = 10.2147/NSS.S62907 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Milner CE, Cote KA | title = Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping | journal = Journal of Sleep Research | volume = 18 | issue = 2 | pages = 272–281 | date = June 2009 | pmid = 19645971 | doi = 10.1111/j.1365-2869.2008.00718.x | s2cid = 22815227 | doi-access = free }}</ref><ref>{{cite book | vauthors = Lovato N, Lack L |title=The effects of napping on cognitive functioning |year=2010 |isbn=978-0-444-53702-7 |series=Progress in Brain Research |volume=185 |pages=155–166 |doi=10.1016/B978-0-444-53702-7.00009-9 |pmid=21075238 }}</ref> Circadian rhythms also play a part in the [[reticular activating system]], which is crucial for maintaining a state of consciousness. A reversal{{Clarify|date=April 2019}} in the sleep–wake cycle may be a sign or complication of [[uremia]],<ref>{{cite web |date=10 May 2006 |title=Renal Failure, Acute |url=http://www.emedicine.com/emerg/topic500.htm |access-date=2008-08-03 |publisher=eMedicine from WebMD |vauthors=Sinert T, Peacock PR}}</ref> [[azotemia]] or [[acute kidney injury]].<ref>{{cite journal | vauthors = Maung SC, El Sara A, Chapman C, Cohen D, Cukor D | title = Sleep disorders and chronic kidney disease | journal = World Journal of Nephrology | volume = 5 | issue = 3 | pages = 224–232 | date = May 2016 | pmid = 27152260 | pmc = 4848147 | doi = 10.5527/wjn.v5.i3.224 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Nakano S, Uchida K, Kigoshi T, Azukizawa S, Iwasaki R, Kaneko M, Morimoto S | title = Circadian rhythm of blood pressure in normotensive NIDDM subjects. Its relationship to microvascular complications | journal = Diabetes Care | volume = 14 | issue = 8 | pages = 707–711 | date = August 1991 | pmid = 1954805 | doi = 10.2337/diacare.14.8.707 | s2cid = 12489921 }}</ref> Studies have also helped elucidate how light has a [[Light effects on circadian rhythm|direct effect]] on human health through its influence on the circadian biology.<ref>{{cite journal | vauthors = Figueiro MG, Rea MS, Bullough JD | title = Does architectural lighting contribute to breast cancer? | journal = Journal of Carcinogenesis | volume = 5 | pages = 20 | date = August 2006 | pmid = 16901343 | pmc = 1557490 | doi = 10.1186/1477-3163-5-20 | doi-access = free }}</ref>