We spend an about one-third of our lives – approximately 25 years – doing it.
Most of what we know about it has only been discovered in the last 25 years.
It’s one of the few things that none of us can live without.
The late comedian and author George Carlin once said of sleep:
People say, “I’m going to sleep now,” as if it were nothing. But it’s really a bizarre activity. “For the next several hours, while the sun is gone, I’m going to become unconscious, temporarily losing command over everything I know and understand. When the sun returns, I will resume my life.”
If you didn’t know what sleep was, and you had only seen it in a science fiction movie, you would think it was weird and tell all your friends about the movie you’d seen.
Indeed, sleep is a bizarre activity. We know we need it, and we feel terrible when we are sleep-deprived – but experts still aren’t entirely sure WHY we sleep.
While much about sleep remains a mystery, some of what we DO know is truly fascinating.
Here are 30 interesting, curious, and downright bizarre facts about sleep.
1. According to The Australian National Sleep Research Project, the record for sleep deprivation is 18 days, 21 hours, 40 minutes.
2. Randy Gardner is the holder of the scientifically documented record for the longest period a human has intentionally gone without sleep not using stimulants of any kind. In 1964, he stayed awake for 264.4 hours (11 days 24 minutes). He was 16 years old at the time, and the experiment was attended by Stanford sleep researcher Dr. William C. Dement.
3. Nearly 2/3 of Americans don’t get enough sleep.
4. An estimated 50-70 million American adults have sleep or wakefulness disorders.
5. Research shows we sleep better during a new moon and worse during a full moon, although the reasons are not clear.
6. If it takes you less than five minutes to fall asleep at night, you are likely sleep deprived. The ideal is between 10 and 15 minutes, meaning you’re still tired enough to sleep deeply, but not so exhausted you feel sleepy during the day.
7. A parent loses about 350 hours of sleep at night during a baby’s first year.
8. Insomnia is not defined by the sleep you lose each night, but by the drowsiness, difficulty concentrating, headaches, irritability, and other problems it causes each day.
9. Being awake for 16 hours straight decreases your performance as much as if your blood alcohol level were .05% (the legal limit is .08%).
10. In the 17th century, getting up in the middle of the night was normal. People slept in two segments divided by an hour or two of alertness (time for reading, praying, intimacy, or socializing with others).
11. Diaries from the pre-electric-light-globe Victorian era show adults slept 9 to 10 hours a night with periods of rest changing with the seasons in line with sunrise and sunsets.
12. Before alarm clocks were invented, there were “knocker-ups” who went tapping on client’s windows with long sticks until they were awake.
13. In 1915, a Hungarian soldier named Paul Kern was shot in the head by a Russian soldier during World War I. The bullet removed part of his frontal lobe. It didn’t kill him, but it made him unable to sleep. Kern reportedly lived for another 40 years, and the cause of his abnormality was never discovered.
14. Fatal Familial Insomnia (FFI) is a very rare inherited brain disease that impairs the part of the brain called the thalamus, robbing people of the ability to sleep. The first symptoms usually begin in mid-life and may include insomnia that worsens over time and vivid dreams when sleep is achieved. There is no cure, and most sufferers die 6 to 32 months after symptoms begin.
15. Parasomnia is a term that refers to unnatural movements and behaviors during sleep. Examples include somnambulism (sleepwalking), somniloquy (sleep-talking), nightmares, night terrors (sort of like a combination of nightmares and sleepwalking), and sleep paralysis. Some people have even committed crime due to parasomnia, including sleep driving and even murder.
16. People who suffer from a parasomnia called REM sleep behavior disorder (RBD) physically act out their dreams. Symptoms may include kicking, punching, arm flailing, or jumping from bed, talking, laughing, shouting, and screaming (or even profanity). These behaviors can be quite violent in nature and can result in injury to the sufferer or their bed partner.
17. People with a scary-sounding parasomnia known as Exploding Head Syndrome experience “hypnagogic auditory hallucinations” like a loud bang sound, a gunshot, cymbals crashing, or a bomb exploding, while they are sleeping. The syndrome is harmless, other than the sleep-deprivation it can cause.
18. Some people experience a phenomenon called “hypnic jerks,” during which their body jerks involuntarily, often in response to a feeling of falling. Experts say they are normal, and some theorize that as the muscles relax, the brain mistakenly registers that the body is falling, and jolts to “catch” itself.
19. Insufficient sleep impacts your hunger and fullness hormones, including two called ghrelin and leptin. When you are sleep-deprived, your body makes more ghrelin, which tells your body it is time to eat. Leptin tells you that you’ve eaten enough, but when you are not getting enough sleep, levels drop – signaling your brain to eat more. To make matters worse, levels of cortisol, a stress hormone that signals your body to conserve energy to fuel your waking hours, also spike when you are sleep-deprived. The result? You are a lot more likely to hang on to body fat and weight loss will be significantly more difficult.
20. A scientific study done in 1998 showed that you can reset your body’s internal clock by shining light on the back of your knees. Researchers say those treated with the light had their biological clocks advanced or delayed up to three hours, enough to overcome the fatigue associated with familiar forms of jet lag or insomnia. To this day, scientists still can’t explain why this works.
21. You are less likely to have a car accident when daylight savings time ends. Statistics show that the extra hour of sleep reduces accidents.
22. The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster, the Chernobyl nuclear accident, the 1999 crash of American Airlines flight 1420, and the 2001 Canadian National train wreck have all been attributed to human errors in which sleep-deprivation played a role.
23. In a 2013 poll, more than half of pilots in the UK admitted they have fallen asleep in the cockpit of a passenger plane. And, alarming research revealed that one in six commercial pilots has woken up at the controls to find that their copilot is dozing too.
24. The National Highway Traffic Safety Administration estimates that fatigue is a cause in 100,000 auto crashes and 1,550 crash-related deaths a year in the U.S. The problem is greatest among people under 25 years old.
25. Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. Unfamiliar noise, and noise during the first and last two hours of sleep, has the greatest disruptive effect on the sleep cycle.
26. The “natural alarm clock” which enables people to wake up around the time they want to (without using an actual alarm clock) is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up.
27. Insomnia is often a natural part of the grieving process, and taking sleep aids can disrupt it.
28. It is estimated that 75% of people today dream in color. Before color television existed, only 15% did.
29. Somniphobia (also known as hypnophobia) is the often irrational and excessive fear of sleep. It may result from a feeling of control loss, chronic nightmares, or anxiety over the loss of time that could be spent accomplishing tasks or maximizing leisure time instead of sleeping.
30. Humans are the ONLY animal known to willingly delay sleep, and it’s a fairly recent phenomena related to the invention of electric lights, and has gotten worse since television, the internet, and smartphones were invented.