Importance of Sleep

Sleep plays a vital role for our physical and mental health. What we do in a day largely depends on how well we slept last night. Having nice sleep is an art which need to be learnt by each of us. Just like food and oxygen are necessary for our life, sleep is also necessary. During sleep, your mind recollects all the data fed through the day, recycles unnecessary stuff, modifies certain data and strongly fixes the data which are very important. Imagine your laptop which is full of files and never reviewed, in that situation, your laptop starts hanging. Just like this, if you do not sleep properly, you will not able to do work throughout the day as data of earlier days are not reviewed and processed. Deep sleep is must for a better health. 
Sudden disturbance from deep sleep (such as car crash) can result in harm over time. It can result in some chronic health problems. It affects how you think, work, react, learn along with many more aspects.

Importance of Sleep
  • Lack of sleep increases blood pressure and cholesterol levels which increases the probability of heart attack.
  • Proper sleep reduces stress and stress creating hormones which results in overall hormonal balance in the body.
  • Sleep boosts memory. While we are at sleep, our brain processes all the data, memories, events, feelings and experiences and sharpens the memory.
  • Researches have found that good sleep helps in reducing weight. Lack of sleep affects the levels of ghrelin and leptin hormones which are responsible for our appetite.
  • Sleep reduces stress hormones which ultimately reduces chronic inflamation disorders like periodontitis, atherosclerosis and rheumatoid arthritis.
  • A good night's sleep refreshes mind and makes us more active and alert on the following day.
  • Small napping during a day results in increased focus and concentration and makes us more productive.
  • Appropriate sleep reduces the chances of depression.
  • During sleep, cells produce more protein which repairs damaged cells.
Sleeping Hours

Though it depends on many factors like your life style, work load, calories lost during work, normal sleeping hours can be prescribed as below:

  • Newborn baby upto 2 months old   >>   12 - 18 hours
  • 3 months to 1 year old                   >>   12 - 14 hours
  • 1 to 3 years old                              >>   12 - 14 hours
  • 3 to 5 years old                              >>   11 - 13 hours
  • 5 to 12 years old                            >>   10 - 11 hours
  • 12 to 18 years                                >>   8.5 - 10 hours
  • Adult (18+)                                     >>  7.5 -10 hours

Amazing facts about sleep
  • The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses.
  • People can take cat naps with their eyes open without even being aware of it.
  • Anything less than five minutes to fall asleep at night means you're sleep deprived.
  • A new baby typically results in 400-750 hours lost sleep for parents in the first year.
  • The continuous brain recordings that led to the discovery of REM (rapid eye-movement) sleep were not done until 1953, partly because the scientists involved were concerned about wasting paper.
  • Dreams, once thought to occur only during REM sleep, also occur (but to a lesser extent) in non-REM sleep phases. 
  • No-one knows if other species dream but some do have sleep cycles similar to humans.
  • Elephants sleep standing up during non-REM sleep, but lie down for REM sleep.
  • Some scientists believe we dream to fix experiences in long-term memory, i.e. we dream about things worth remembering.
  • Dreams may not serve any purpose at all but be merely a meaningless byproduct of two evolutionary adaptations - sleep and consciousness.
  • British Ministry of Defence researchers have been able to reset soldiers' body clocks so they can go without sleep for up to 36 hrs.
  • Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%.
  • The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role.
  • Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. 
  • The "natural alarm clock" which enables some people to wake up more or less when they want to is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up.
  • Some sleeping tablets, such as barbiturates suppress REM sleep, which can be harmful over a long period.
  • In insomnia following bereavement, sleeping pills can disrupt grieving.
  • Tiny luminous rays from a digital alarm clock can be enough to disrupt the sleep cycle even if you do not fully wake. The light turns off a "neural switch" in the brain, causing levels of a key sleep chemical to decline within minutes.
  • A night on the grog will help you get to sleep but it will be a light slumber and you won't dream much.
  • After five nights of partial sleep deprivation, three drinks will have the same effect on your body as six would when you've slept enough.
  • Humans sleep on average around three hours less than other primates like chimps, rhesus monkeys, squirrel monkeys and baboons, all of whom sleep for 10 hours.
  • Ten per cent of snorers have sleep apnoea, a disorder which causes sufferers to stop breathing up to 300 times a night and significantly increases the risk of suffering a heart attack or stroke.
  • Snoring occurs only in non-REM sleep.
  • Teenagers need as much sleep as small children (about 10 hrs) while those over 65 need the least of all (about six hours). For the average adult aged 25-55, eight hours is considered optimal.
  • Some studies suggest women need up to an hour's extra sleep a night compared to men, and not getting it may be one reason women are much more susceptible to depression than men.
  • Diaries from the pre-electric-light-globe Victorian era show adults slept nine to 10 hours a night with periods of rest changing with the seasons in line with sunrise and sunsets.
  • Most of what we know about sleep we've learned in the past 25 years.
  • As a group, 18 to 24 year-olds deprived of sleep suffer more from impaired performance than older adults.
  • Experts say one of the most alluring sleep distractions is the 24-hour accessibility of the internet.
Sleep and Disease