The Proliferation of Sleep Research
Over the past ten years, sleep research has accelerated at a pace never seen before. Organizations like the Sleep Research Society, the Centers for Disease Control and Prevention, the Mayo Clinic and the National Institutes of Health have shed more light on the importance of sleep. It is now known as the "third pillar" of good health.
To keep track of key findings, we track updates from trusted sources as they are published. Our goal is to simplify the key facts that come out of that research into our resources throughout the site and the statistics below. If you feel we have missed something that you think should be included, please let us know.
General Sleep Statistics
Average Sleep Times
- Americans sleep 6.8 hours per day on average, which hasn't changed much from Gallup polls in the 1990s and 2000s, but is down more than an hour from 1942.1
- 59% of Americans get 7 or more hours of sleep at night. In 1942, 84% met the standard of getting 7-9 hours per night of sleep.1
- The older the age group, the more they report sleeping. Americans aged 65 and over report getting the most sleep, while 18-29-year-old report the least.
|Group||Sleep 6 hours or less||Sleep 7 hours or more|
|18-29 year olds|
|30-49 year olds|
|50-64 year olds|
|65+ year olds|
|Less than $30,000 annual household income|
|Between $30,000 to $75,000 annual household income|
|$75,000 or more annual household income|
|Have children under 18|
|Don't have children under 18|
Source: Gallup, Dec. 5-8, 2013
Sleep Needs Statistics
Sleep needs by age as defined by the June 13, 2016, American Academy of Sleep Medicine (AASM) recommendations that the American Academy of Pediatrics (AAP) has endorsed.2
|Age||Recommended Amount of Sleep|
|Infants aged 4-12 months||12-16 hours a day (including naps)|
|Children aged 1-2 years||11-14 hours a day (including naps)|
|Children aged 3-5 years||10-13 hours a day (including naps)|
|Children aged 6-12 years||9-12 hours a day|
|Teens aged 13-18 years||8-10 hours a day|
|Adults aged 18 years or older||7–8 hours a day|
- Women on average sleep five to 28 minutes longer than men.3 The NIH found a variety of factors tied to this including differences in average lifestyle and employment.
- On average, women need 20 minutes more sleep per night.4
Sleep Deprivation Statistics
- Adults need 7 hours or more of sleep per night for optimal health.5 The statistics below define short sleep as less than 24 hours of sleep in 24 hours.
Prevalence of Short Sleep Duration (<7 hours) for Adults Aged ≥18 Years, by County, United States, 2014
- About one in four people aged 18 to 24 say that they don't sleep well because of technology.5
- Sleep deprivation increases the expectation of gains and decreases the estimation of possible losses when gambling.6
- Decision making in "high-stakes, real-world situations" is impaired when someone is experiencing sleep loss.7
- Shift Work Sleep Disorder is a recognized medical condition for 20% of U.S. shift workers.8
- 45% of Americans claim that poor sleep has made an impact on their daily life at least once in the last 7 days.33
- More than 50% of Americans have taken a nap in the last 7 days. 23% took a nap 1-2 days, 13% took a nap 3-4 days, 17% took a nap at least 5 days. This may suggest that many Americans undersleep, though many countries take afternoon "siestas," and some sleep researchers theorize that humans may be wired to sleep in 2 sessions per day (in 2 sleep phases).
Sleep Disorders Statistics
Sleep disorders are very common. The NIH compiled the data below to support clinical practice guidelines for sleep disorders.9
|Obstructive sleep apnea*||14%|
|Restless legs syndrome*||2%|
|Delayed sleep-wake phase disorder||10%|
|Advanced sleep-wake phase disorder||1%|
|Shift worker disorder||2%|
|*Data from Indian adult population|
Insomnia is a sleep disorder that leads to habitual sleeplessness or an inability to sleep.
- The yearly workplace cost in the US due to insomnia is an estimated $63.2 billion.10
- One in four women suffers from insomnia.11 This makes them twice as likely as men to have insomnia.12
- Approximately 6% of adults suffer from insomnia.13
Hypersomnia is a sleep disorder that leads to excessive daytime sleepiness or time spent sleeping.
- 4% to 6% of the general population has hypersomnia.14
- Sleep apnea syndrome leads to hypersomnia, and there is a higher prevalence of this disorder in men.15
- Narcolepsy only affects 0.026% of the general population. It is caused by the inability to regulate sleep-wake cycles normally. 16
Obstructive Sleep Apnea
Obstructive sleep apnea syndrome (OSAS) is a potentially serious sleeping disorder that causes people to repeatedly stop and start breathing during sleep.
- 5% to 20% of the adult population is affected by OSAS when assessed with sleep tests.17
- It is seen in 1% to 3% of children of preschool age.18
- OSAS prevalence is as high as 10% to 20% in children who habitually snore.19
Restless Legs Syndrome
Restless legs syndrome (RLS) is a disorder characterized by overwhelming urges to move the legs to relieve unpleasant twitching or tickling sensations.
- 11% to 29% of pregnant women are affected by RLS.
- 25% to 50% of patients with end-stage renal disease have Restless Legs Syndrome
- Limb twitching during sleep occurs in 80% of patients with RLS.20
Delayed Sleep-Wake Phase Disorder
Delayed sleep-wake phase disorder (DSWPD) is a sleep disorder characterized by a delayed day and night cycle often causing someone to fall asleep and wake later in the day.
Note that statistics vary widely on this condition as the consistency around definitions and diagnostic criteria tend to vary widely.
- 51% of patients with DSWPD have had a lifetime history of depression.
- 59% of adolescents with this disorder demonstrated poor academic performance and 45% had behavioral problems.21
- A prevalence of up to 8 percent has been reported in American teenagers.22
Advanced Sleep-Wake Phase Disorder
Advanced Sleep Phase Disorder (ASPD), otherwise known as Advanced Sleep Phase Syndrome (ASPS), is a sleep disorder characterized by a shift in the circadian rhythm. This shift typically causes someone to go to bed earlier and wake up earlier. This is characterized by the correct quantity of sleep at undesired times of the day. Approximate averages are 8-9 pm bedtimes and 4-5 am awakenings. This disorder is not yet commonly understood.
- There is a 50% chance of passing ASPD on to children.23
Shift Worker Disorder
Shift work sleep disorder (SWSD) is a sleep disorder characterized by excessive sleepiness and insomnia in people whose work schedules overlap with normal sleep times.
- 20% of the working population in Europe and North America is engaged in shiftwork24
- The sleep-wake disturbance is severe enough to warrant diagnosis as SWSD in about 5 to 10 percent of night-shift workers.
- 37.5% of post-night-shift drives have been considered unsafe during testing.25
Obesity and Sleep Statistics
Being overweight can affect sleep, and poor sleep can make it more likely to put on weight. Researchers from Johns Hopkins University School of Medicine studied 77 overweight volunteers with either prediabetes or type 2 diabetes. Many had issues getting high-quality sleep. Half of the group went on a weight-loss diet and exercise program, and the other half just followed the diet. After 6 months, both groups lost an average of 15 pounds and reduced their belly fat by 15%. The researchers concluded that a reduction in belly fat is a good way to improve sleep.35
Sleep apnea is a sleep disorder where a sleeper will experience apneas or pauses in breathing while sleeping. Sufferers of sleep apnea often snore loudly, stop breathing during the night many times, often wake up with a dry mouth and/or headache, are tired during the day, and have trouble focusing. The chances of sleep apnea are increased by being overweight, as fat around the upper airway can block the airway, especially when sleeping on the back.
- A 20-year review of children ages 6-17 years with obesity-associated diseases found that hospital discharges for sleep apnea increased 436%.
- 18 million adult Americans have sleep apnea.
- A 1999 study from the University of Chicago found that sleep debt accumulated over a few days can slow metabolism and disrupt hormone levels. 11 healthy young adults were restricted to 4-6 hours of sleep per night. Their ability to process sugar in the blood had reduced, in some cases, to the level of diabetics.33
- The Wisconsin Sleep Cohort Study concluded that short sleep was associated with 15.5% lower leptin levels and 14.9% elevated grehlin levels. Leptin is the hormone that suppresses appetite, and ghrelin stimulates appetite, increased food intake, and promotes fat storage.34
- Oregan State University researchers found that people who exercise 150 minutes per week slept better and felt more alert during the day compared to those who don't.35
- Researchers Guglielmo Beccuti and Silvana Pannain explain that recent epidemiological and laboratory evidence confirms previous findings of an association between sleep loss and an increased risk of obesity. Sleep loss has been shown to result in decreased insulin sensitivity, increased evening levels of cortisol (the stress hormone that prevents sleep), increased levels of ghrelin (increasing appetite), and decreased levels of leptin (reducing the feeling of satiation). They further explain that the worldwide prevalence of obesity has doubled since 1980, and this epidemic has been paralleled by a trend of reduced sleep.36
- A 6-year Italian study found that every extra hour of sleep decreased the incidence of obesity by 30%.36
- Lack of sleep can negatively affect eating habits. One study found an increased caloric intake in 12 normal-weight healthy adults after 4 hours of sleep.37
- Another study reported a 14% increase in caloric intake, especially for carbohydrates in 10 healthy adults who had slept 4.5 hours.38
Anxiety Disorders & Sleep Statistics
Sleep issues are very common with people with anxiety disorders and depression. Some anxiety disorders such as generalized anxiety disorder and post-traumatic stress disorder have even included nightmares or insomnia in their definitions.
Anxiety usually functions as an alarm bell for potential danger, but in anxiety disorders the alarms may be intense, frequent, or even continuous. This level of arousal leads to issues with sleep.
- 24% to 36% of insomnia sufferers have an anxiety disorder, while 27% to 42% of those with hypersomnia have anxiety disorders.40
- In another study, researchers found that insomnia appeared before the anxiety disorder in 18% of the subjects. 38.6% of the time, insomnia and the anxiety disorder appeared around the same time. 43.5% of the time, anxiety appeared before insomnia.40
- In a study published in the Archives of General Psychiatry, researchers found that 68% of subjects had difficulty falling asleep, while 77% had restless sleep.41
Odds ratios for specific anxiety disorders associated with lifetime sleep disturbances (adapted from Breslau et al 39).40
|Generalized Anxiety Disorder||7.0 (2.8-17.2)||4.5 (1.5-15.3)||4.8 (1.5-15.2)|
|Panic Disorder||5.3 (2.0-13.6)||4.3 (1.3-14.8)||8.5 (3.1-23.5)|
|Obsessive Compulsive Disorder||5.4 (2.0-14.8)||1.2 (0.1-9.7)||13.1 (4.8-35.7)|
|Phobic Disorder||1.5 (1.0-2.3)||29 (1.8-4.8)||4.0 (2.5-6.5)|
|Any Anxiety Disorder||2.4 (1.6-3.5)/td>||3.3 (2.0-5.4)||4.5 (2.8-3.7)|
- The majority of patients with panic disorder experience nocturnal panic attacks. Up to 18% of panic attacks happen while asleep. Ambulatory heart rate changes in patients with panic attacks. 42
- It's been estimated that 60% to 70% of patients had general anxiety disorder (GAD), suggesting that insomnia is one of the core facets of GAD.43
- Sufferers of post-traumatic stress disorder (PTSD) commonly complain of nightmares and insomnia. It's been estimated that 96% of Holocaust survivors had insomnia and 83% had recurrent nightmares.44
- One study found that PTSD sufferers estimate that they lay awake more than half of the night.45
Depression and Sleep Statistics
Depression and poor sleep occur so commonly together that researchers aren't sure if one is causing the other, or if they're just associated. Both insomnia and sleeping too much could be signs of depression.
- It's estimated that 75% of patients with depression also have insomnia.46
- According to the National Sleep Foundation, those with insomnia have a 10 times greater risk of developing depression compared to those who get enough restful sleep.
- According to the journal Lancet Psychiatry, people with mental health disorders showed improvement from increased amount and quality of sleep.
- Night owls are more likely to be depressed compared to early birds, and researchers aren't sure why.
- A Japanese study from 2006 analyzed data from 24,686 people aged 20 and above and found that people who sleep less than 6 hours and more than 8 hours tend to be depressed, creating a U-shaped association with symptoms of depression.47
- Jones, Jeffrey. (December 19, 2013). https://news.gallup.com/poll/166553/less-recommended-amount-sleep.aspx
- American Academy of Pediatrics Endorsement of Childhood Sleep Guidelines. https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/American-Academy-of-Pediatrics-Supports-Childhood-Sleep-Guidelines.aspx
- Burgard SA, Ailshire JA. Gender and Time for Sleep among U.S. Adults. Am Sociol Rev. 2013;78(1):51-69. doi:10.1177/0003122412472048
- Dr. Jim Horne. " Who REALLY needs more sleep - men or women? One of Britain's leading sleep experts says he has the answer." Daily Mail, January 26, 2010. https://www.dailymail.co.uk/health/article-1246029/Who-REALLY-needs-sleep--men-women-One-Britains-leading-sleep-experts-says-answer.html
- TIME Mobility Poll, in cooperation with Qualcomm. August 2012. https://www.qualcomm.com/media/documents/files/time-mobility-poll-in-cooperation-with-qualcomm.pdf
- Sleep Deprivation Can Threaten Competent Decision-making. American Academy of Sleep Medicine. May 5, 2007. https://www.sciencedaily.com/releases/2007/05/070501075246.htm
- Oxford University Press. https://academic.oup.com/journals
- Shift Work Sleep Disorder. https://my.clevelandclinic.org/health/diseases/12146-shift-work-sleep-disorder
- Gupta R, Das S, Gujar K, Mishra KK, Gaur N, Majid A. Clinical Practice Guidelines for Sleep Disorders. Indian J Psychiatry. 2017;59(Suppl 1):S116-S138. doi:10.4103/0019-5545.196978.
- Kessler RC, Berglund PA, Coulouvrat C, Hajak G, Roth T, Shahly V, Shillington AC, Stephenson JJ, Walsh JK. Insomnia and the performance of US workers: results from the America insomnia survey. Sleep. 2011 Sep 1;34(9):1161-71. doi: 10.5665/SLEEP.1230. Erratum in: Sleep. 2011;34(11):1608. Erratum in: Sleep. 2012 Jun;35(6):725.
- Kessler, R.C., Berglund, P.A., Coulouvrat, C., Hajak, G., Roth, T., Shahly, V., et al. (2011). "Insomnia and the performance of US workers: results from the America insomnia survey. https://www.ncbi.nlm.nih.gov/pubmed/21886353 34(9): 1161-1171.
- Deirdre Conroy, PH.D. (June 13, 2016). https://healthblog.uofmhealth.org/health-management/3-reasons-women-are-more-likely-to-have-insomnia
- Roth T. Insomnia: definition, prevalence, etiology, and consequences. J Clin Sleep Med. 2007;3(5 Suppl):S7-S10.
- Billiard M., Dauvilliers Y. Narcolepsy In: Billiard M, ed. Sleep: Physiology Investigations and Medicine. New York, NY: Kluwer Academic/Plenum Publishers. 2003:403–406.
- Billiard M. Hypersomnias. In: Billiard M, ed. Sleep: Physiology Investigations and Medicine. New York, NY: Kluwer Academic/Plenum Publishers.
- Guilleminault C, Tilkian A, Dement WC. The sleep apnea syndromes. Annu Rev Med. 1976;27:465-84. doi: 10.1146/annurev.me.27.020176.002341.
- Weaver TE, George CFP, “Cognition and Performance in Patients with Obstructive Sleep Apnea,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1194-1205.
- Mindell JA, Owens JA. Diagnosis and Management of Sleep Problems. A Clinical Guide to Pediatric Sleep. Philadelphia. PA: Lippincott Williams and Wilkins, 2003.
- Marcus CL. Pathophysiology of childhood obstructive sleep apnea: current concepts. Resp Physiol. 2000;119:143-154.
- Mansur A, Castillo PR, Rocha Cabrero F, et al. Restless Legs Syndrome. [Updated 2021 Apr 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430878/
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- Saxvig IW, Pallesen S, Wilhelmsen-Langeland A, Molde H, Bjorvatn B. Prevalence and correlates of delayed sleep phase in high school students. Sleep Med. 2012 Feb;13(2):193-9. doi: 10.1016/j.sleep.2011.10.024.
- Paine SJ, Fink J, Gander PH, Warman GR. Identifying advanced and delayed sleep phase disorders in the general population: a national survey of New Zealand adults. Chronobiol Int. 2014 Jun;31(5):627-36. doi: 10.3109/07420528.2014.885036.
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