75 Refreshing Facts About Sleep [2023]

Written by
 Purple Staff
Last Updated
September 26, 2023
min read

A good night’s rest isn’t as common as you think. In fact, 1 in 3 U.S. adults don’t get enough sleep, despite knowing proper rest is essential for proper cognitive function and maintenance of physical health. What's more, consistently poor sleep can exacerbate risk factors associated with common sleep disorders, making it even harder to get the rest you need.

Facts about sleep show that insufficient rest impacts people of all ages, from high school students to seniors. The prevalence of sleep disorders is far-reaching with a myriad of factors promoting lack of sleep, even when your cozy mattress is calling your name. But how do you quantify sleep so that you can understand it better?

The answer is statistics. Numbers tell us a lot about the ins and outs of sleep and why it’s easier to achieve it at some times more so than others. 

Read on to learn more facts about sleep, how sleep works, and how widespread insufficient sleep is throughout all ages in the United States.

Fun Facts About Sleep

1. About one-third of Americans report “poor” or “fair” sleep from the previous night. That’s almost 84 million people. The remaining sleepers are fairly split in sleep quality — one-third report “very good” or “excellent,” and one-third report “good” sleep. (Gallup)

2. Women sleep more than men but experience more difficulty falling asleep. (SleepCycle)

3. New Zealand is the sleepiest nation, with sleepers spending seven hours and 27 minutes in bed a night, on average. The U.S. ranks 16 with an average of seven hours and six minutes of nighttime slumber. (World Population Review)

4. India reports the best sleep satisfaction, with 67% of adults either somewhat or completely happy with their sleep quality. (Phillips)

5. Humans have an innate, genetically determined circadian rhythm that naturally determines when people feel sleepy or alert. Experts have classified four chronotypes that group those with similar circadian rhythms:

  • Dolphins are erratic sleepers with unpredictable schedules. They account for about 10% of the population.
  • Lions are early birds who wake up before the sun in the morning and go to bed early. They are about 20% of the population
  • Bears follow the sun for rising and sleeping. They account for about 55% of the population.
  • Wolves are night owls who wake later in the morning and stay up late. They are about 15% of the population. (Sleep Doctor)

6. Side sleeping is the most popular position (54.1%), followed by back sleeping (37.5%) and stomach sleeping (7.3%). (Nature and Science of Sleep Journal)

7. Koalas are the world’s sleepiest animal. They spend most of their time snoozing, up to 22 hours a day. (BBC Wildlife Magazine)

8. Octopuses change skin colors and texture during their Active Sleep stage. (Science)

9. There are four stages of sleep: Stage one (N1 or awake), stage two (N2 or light), stage three (N3 or deep), and rapid eye movement REM sleep. Stages one through three are non-rapid eye movement phases (NREM). (StatPearls)

A chart shows the average duration of each sleep cycle throughout the night.

10. Typically, sleepers experience 4 to 6 complete sleep cycles during slumber in this order: N1, N2, N3, N2, REM. A complete cycle lasts approximately 90 minutes long. (StatPearls)

11. Stage two of sleep lasts the longest at around 25 minutes in the first cycle and extends with each repeated cycle, totaling about 45% of total sleep. Stage 3 and REM sleep account for about 25% of total sleep. (StatPearls)

12. Body temperature drops about 1 to 2 degrees Fahrenheit while asleep, which researchers think may help us to more easily drop into dreamland. (Current Opinion in Physiology)

Sleep Health Facts

13. Poor sleep can lead to many health issues, including an increased risk for obesity, type 2 diabetes, heart disease, high blood pressure, stroke, declining mental health, and early death. (Centers for Disease Control and Prevention)

14. Inadequate sleep can negatively impact cognitive performance, particularly in attention spans, emotional capacities, judgment, and reaction times. (Journal of Experimental Psychology)

15. Poor sleep quality and sleep deprivation are linked to elevated blood pressure, increased heart rate, and inflammation, all of which increase the risk of cardiovascular disease. (American Heart Association)

16. Sleep deprivation can lead to various hormone imbalances, including cortisol, insulin, ghrelin, leptin, melatonin, serotonin, dopamine, thyroid, and sex hormones. (Sleep Science)

17. Chronic sleep deprivation can weaken the immune system by hindering cytokine production, which helps manage inflammation in the body. (Mayo Clinic)

A graphic lists the health impacts of sleeping less than 7 hours a night with an illustration of a tired man.

18. It takes just one night of poor sleep to have an adverse effect, including a bad mood, a lack of productivity, or an increased risk of being in a motor vehicle accident. (CDC)

19. Adult drivers who either snore or sleep six or fewer hours per day reported falling asleep at the wheel more often. In 2020, 633 deaths were attributed to drowsy driving, but these numbers could total 6,000 or more. (CDC)

20. Researchers believe an extra 60 to 90 minutes of sleep can improve one’s overall health and mental well-being. (American Psychological Association)

Sleep and Mental Health Facts

Sleep and mental health are intimately connected, with daily stressors generally being credited for most instances of sleep deprivation and the development of sleep disorders. That said, their relationship is more cyclical than causal.

21. Oversleeping or undersleeping can result from underlying mental health issues, but a lack of sleep can also exacerbate an individual’s depression or anxiety. (Columbia University)

22. Individuals who sleep less than six hours a night on average are almost three times more likely to suffer from mental health concerns. (Preventing Chronic Disease

A graphic explains how a lack of sleep impacts mental health with an illustration of an alarm clock.

23. As many as 90% of individuals report sleep disturbances as a symptom of depression. The most common struggles relate to insomnia, excessive fatigue, and sleep deprivation. (Sleep and Biological Rhythms Journal)

24. Many otherwise healthy individuals who experience a poor night’s sleep report increased anxiety the following day. (Columbia University)

25. Roughly 70% of those with PTSD experience insomnia symptoms. This is largely due to a fear of sleep (nightmares) and often coincides with sleep apnea. (Frontiers in Psychiatry)

26. One study found that 43% of adults often feel too stressed to sleep, causing them to lie awake unable to fall asleep at night. (APA)

Sleep Disorder Facts

Sleep disorders are medical conditions that interfere with a person's ability to get sufficient sleep. Sleep disorders are usually uncontrollable and need to be treated by a medical professional. 

These disorders are increasingly common in the United States and contribute to the large number of adults who aren’t getting proper sleep.

27. An estimated 70 million Americans currently experience at least one sleep disorder. (American Academy of Sleep Medicine)

28. Over 80 sleep disorders exist but the most common are circadian rhythm sleep disorders (like shift work sleep disorder), insomnia, hypersomnia (like narcolepsy), restless leg syndrome, sleep apnea, parasomnias (like sleepwalking and sleep eating), and night terrors. (Cleveland Clinic)

A list of the common sleep disorders with their prevalence shown in bar charts.

29. Narcolepsy is a relatively rare sleep disorder that affects 44.3 in 100,000 people in the United States. People with this condition experience overwhelming daytime sleepiness and "sleep attacks'' during the day. (Journal of Clinical Sleep Medicine)

30. There are two types of narcolepsy: NT1 and NT2. Narcolepsy cases are often sporadic or due to a medical condition. However, NT1 can be hereditary for a small percentage of individuals. (National Institute of Neurological Disorders and Stroke)

31. 40% of women and roughly 57% of men snore while sleeping. However, the prevalence could be greater as snoring can go unnoticed by a sleeper or their sleeping partner. (MSD Manual)

32. Nearly 1 billion people have obstructive sleep apnea (OSA) worldwide. OSA happens when the muscles supporting the tissues within a person's airway relax, narrowing and temporarily obstructing breathing.

33. While OSA is more common in men, the difference is slight. 27.3% of men and 22.5% of women around the globe have OSA. The gap also closes as women age. (Medical Principles and Practice, 2021)

34. Central sleep apnea (CSA) is much less prevalent. Only 1.7% of middle-aged adults and 12.1% of older adults suffer from CSA. A person has central sleep apnea when their breathing starts and stops several times while sleeping. This is because their brains don't send the correct signals to the rest of their bodies. (Current Pulmonology Reports)

35. Nearly one-half of people talk in their sleep. (Amerisleep)

36. 11% of adults sleepwalk, and 7% have either sustained or witnessed an injury while sleepwalking. (Amerisleep)

37. Getting up more than once to use the bathroom is called “nocturia,” which affects roughly one-third of adults over the age of 30. (American Urological Association)

38. One study on sleep disorders reported 2%–6% of participants indicating that they experienced "sexsomnia." This referred to the act of waking up in the middle of the night to get intimate with a partner. (Sleep and Vigilance)

READ MORE: Sleep Apnea Statistic

Sleep Deprivation Statistics

Sleep deprivation is the condition of not sleeping the age-based recommended amount of hours each night due to one’s lifestyle. Chronic short sleep durations (or the beginnings of insomnia) can negatively impact both physical and mental health.

39. Most American adults aren’t getting the proper amount of sleep per night. Only one-third of Americans sleep between seven and nine hours on average a night. (Gallup)

40. The number of adults who aren’t getting enough sleep hasn’t changed much in the past seven years. (CDC)

41. Females are more likely than males to experience insufficient sleep and insomnia. (Frontiers in Psychiatry)

42. Nearly one-half of college students report fatigue at least five times a week. (Statista)

43. Over one-third of American children and teens, both male and female, experience short sleep durations. This is consistent across all age ranges from one year to 17 years. (Statista)

44. About 40% of people with insomnia symptoms tend to be affected by a mental health disorder. (MSD Manual)

45. Adults who report short sleep durations and/or interrupted sleep also experience a 31% reduction in positive moods and an increase in feelings of depression the following day. (John Hopkins Medicine; Sleep and Biological Rhythms Journal)

Sleep Hygiene Facts

Sleep hygiene refers to all the habits and choices people make around sleep. This can include bedtimes, nighttime routines, methods to fall asleep, and more. Good sleep hygiene is characterized by routines that support quality sleep, while bad hygiene usually lacks structure and regularity. 

46. 41% of Americans have a consistent bedtime ritual. Some read a book, journal, or watch television while others scroll their phones or create to-do lists for the next day. (Sleepopolis

47. On average, people spend 26 minutes a day on their nighttime routines. (SWNS Digital)

A list of 10 common nighttime routines, including reading and preparing for the next day.

48. Gen Z prioritizes sleep more so than other generations. They are more likely to skip a nighttime routine, like forgetting to brush their teeth (53%) or change into pajamas (47%). (SWNS Digital)

49. Moving around while sleeping and stealing covers are the top sleep disruptions for those who share a bed with a partner. Almost half of these individuals would be willing to consider sleeping in separate beds for better sleep. (Serta Simmons)

50. 15% of Americans use sleep trackers, with women 50% more likely to use them than men. Almost half of those who use sleep trackers influence positive sleep habits. (Statista, Sleep Science)

51. Sleep tracking apps were the second most popular health-related app purchased in 2022, with 34% of those in a recent survey having purchased them. (Statista)

52. 18.4% of adults use sleep medications, with women almost twice as likely to take them to fall or stay asleep. (CDC)

53. A majority of people (80%) who use prescription sleep medications experience side effects that roll into the following day. Specifically, they report instances of oversleeping, general grogginess, or having trouble concentrating for hours after they wake up. (Sleep Disorders)

54. Melatonin supplements are often used to promote sleep. One research study showed that participants fell asleep on average seven minutes faster and slept about eight minutes longer. (StatPearls)

55. A recent study found that melatonin supplements may contain between -83% and +478% of their listed melatonin content, as they are not FDA-regulated. (StatPearls)

56. Research indicates frequent alcohol consumption decreases sleep quality by 40%. Those who drink several times a week report longer times to fall asleep, less sleep overall, and increased wakings. (JMIR Mental Health)

57. Caffeine has a half-life of five hours in healthy adults, meaning that roughly half of all consumed caffeine will be used up by the body in five hours. When consumed too close to bedtime, it can lead to sleep disruptions. (Institute of Medicine)

Dream Statistics

58. Dreams occur throughout all the sleep cycles but are typically most vivid during the REM stage. (NIH)

59. Most dreams (95%) are forgotten nearly immediately after waking up. (TIME)

60. Blind individuals still experience visual dreams, even if they’ve been blind their entire lives. (Society of Photo-Optical Instrumentation Engineers)

61. Most people dream in colors of varying vividness and only 12% of people report dreaming in black and white. It’s more common for older generations to report dreaming in black and white. One theory to explain this is childhood exposure to black-and-white television. (Conscious and Cognition)

62. It’s hard to know how long people spend dreaming, though it’s thought that it’s about two hours of dreams each night. That’s over 700 hours of dreaming a year. (NIH)

63. The dream recall rates change throughout one’s lifespan. Dream recall is relatively poor as a child, peaks into adulthood, and then diminishes around 60 years old. (NSS)

64. Researchers have many theories on what dreams mean, but many agree that we dream to process events and emotions in our daily lives.

Sleep Facts for Students and Children

Sleep in children can be unpredictable, but it’s just as important for children to meet the recommended amounts of rest needed for development. Encouraging the significance of sleep hygiene and routines encourages children to make healthier sleep decisions later in life.

65. Newborns and babies up to one year old need roughly 14 to 17 hours of sleep per day between naps and shorter nighttime sleeping sessions. (CDC)

66. Young children between ages 1 and 4 require 10 to 14 hours of sleep per night. (CDC)

67. Older children from ages 5 to 12 need 9 to 12 hours of sleep. (CDC)

68. Teens up to 17 years old require 8 and 10 hours of sleep per night. (CDC)

A bar graph shows the amount of sleep that’s recommended each day by age from newborns to seniors.

69. Almost 75% of high school students experience sleep deprivation and sleep less than eight hours a night. Over 40% report 6 hours or less of sleep on average a night. (CDC)

70. About 70% of children with attention-deficit/hyperactivity disorder (ADHD) suffer from disordered sleeping — most commonly with insomnia and increased daytime sleepiness. (Journal of Translational Medicine)

71. Between 30% and 53% of Autistic children experience sleep disorders, particularly insomnia and delayed sleep-wake phase disorder. These sleep disorders can heighten autism symptoms. (Journal of Translational Medicine)

72. Youths (ages 6 to 24 years old) with at least one sleep disorder are 46% more likely to experience suicidal ideations and are three times more likely to visit an emergency room due to suicidal ideations. (Sleep Health)

73. About 20% of children experience a sleepwalking episode. Children are more likely to sleepwalk if their parents did. (Cleveland Clinic)

74. It isn’t until around seven years old that we begin to see ourselves in dreams and dream with narrative structure and emotion. Up until then, dreams often show an absence of people, objects, and events and pair with low recall rates. (NSS)

75. Teenagers’ circadian rhythms naturally delay bedtimes and wake times, which can interfere with their education. Early school start times — before 8 a.m. — can cause social jet lag, which occurs when an individual’s activities disrupt their sleep schedule. Later school start times are associated with overall developmental outcomes, improved energy levels, and less negative moods. (American Academy of Pediatrics Grand Rounds)

Why is Sleep Important?

Sleep is vital for a happy and healthy life, but many people struggle with getting the proper amount of rest per night. This can be attributed to stress, mental health issues, or sleep disorders that may be difficult to manage on your own. 

The primary way to quickly make a difference in your sleep is to ensure you have the proper mattress for your sleep habits. While job responsibilities and the chaos of life will always ensue, a mattress that softens and supports exactly where you need it to while keeping cool throughout the night is the secret to making sleep come easier.

Purple’s GelFlex® Grid is a proprietary sleep innovation that instantly adapts to your shape for a cozy, cradling comfort — with the proper alignment. Use our Mattress Finder for a personalized list of recommendations based on your specific sleep style or view our full mattress selection and make your way toward the rest you deserve!