Two-thirds of adults throughout all developed nations fail to obtain the recommended eight hours of nightly sleep

Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer. Insufficient sleep is a key lifestyle factor determining whether or not you will develop Alzheimer's disease. Inadequate sleep—even moderate reductions for just one week—disrupts blood sugar levels so profoundly that you would be classified as pre-diabetic. Short sleeping increases the likelihood of your coronary arteries becoming blocked and brittle, setting you on a path toward cardiovascular disease, stroke, and congestive heart failure. Sleep disruption further contributes to all major psychiatric conditions, including depression, anxiety, and suicidality

Too little sleep swells concentrations of a hormone that makes you feel hungry while suppressing a companion hormone that otherwise signals food satisfaction

The shorter your sleep, the shorter your life span

Drowsy driving is the cause of hundreds of thousands of traffic accidents and fatalities each year

One person dies in a traffic accident every hour in the United States due to a fatigue-related error. Vehicular accidents caused by drowsy driving exceed those caused by alcohol and drugs combined

Sleep enriches our ability to learn, memorize, and make logical decisions and choices. Sleep recalibrates our emotional brain circuits, allowing us to navigate next-day social and psychological challenges with cool-headed composure

Sleep restocks the armory of our immune system, helping fight malignancy, preventing infection, and warding off all manner of sickness. Sleep reforms the body's metabolic state by fine-tuning the balance of insulin and circulating glucose

The physical and mental impairments caused by one night of bad sleep dwarf those caused by an equivalent absence of food or exercise

Sleep is the single most effective thing we can do to reset our brain and body health each day

For some people, their peak of wakefulness arrives early in the day, and their sleepiness though arrives early at night. These are 'morning types,' and make up about 40 percent of the populace. Others are 'evening types,' and account for approximately 30 percent of the population. They naturally prefer going to bed late and subsequently wake up late the following morning, or even in the afternoon. The remaining 30 percent of people lie somewhere in between morning and evening types, with a slight leaning toward eveningness

An adult's owlness or larkness is strongly determined by genetics

Melatonin is released at nnight

Melatonin helps regulate the timing of when sleep occurs by systemically signaling darkness throughout the organism. But melatonin has little influence on the generation of sleep itself

For every day you are in a different time zone, your suprachiasmatic nucleus can only readjust by about one hour

Sleep pressure is a chemical called adenosine is building up in your brain

Increasing adenosine in the brain is an increasing desire to sleep

Caffeine is the most widely used psychoactive stimulant in the world. It is the second most traded commodity on the planet, after oil

Caffeine works by successfully battling with adenosine for the privilege of latching on to adenosine welcome sites—or receptors—in the brain

Caffeine blocks and effectively inactivates the receptors, acting as a masking agent

Caffeine blocks the sleepiness signal normally communicated to the brain by adenosine. Caffeine tricks you into feeling alert and awake. despite the high levels of adenosine that would otherwise seduce you into sleep

Levels of circulating caffeine peak approximately thirty minutes after oral administration

Caffeine has an average half-life of five to seven hours

De-caffeinated does not mean non-caffeinated. Decaf usually contains 15-30 percent of the dose of a regular cup of coffee

After waking up in the morning, could you fall back asleep at ten or eleven am? If the answer is 'yes,' you are likely not getting sufficient sleep quantity and/or quality. Can you function optimally without caffeine before noon? If the answer is 'no,' then you are most likely self-medicating your state of chronic sleep deprivation

Humans don't just sleep, but cycle through two completely different types of sleep. Non-rapid eye movement, or NREM, sleep, and rapid eye movement, or REM, sleep

REM sleep, in which brain activity was almost identical to that when we are awake, was intimately connected to the experience we call dreaming, and is often described as dream sleep

The cerebral war between the two is won and lost every ninety minutes, ruled first by NREM sleep, followed by the comeback of REM sleep

A key function of deep NREM sleep is to do the work of weeding out and removing unnecessary neural connections. In contrast, the dreaming stage of REM sleep plays a role in strengthening those connections

Humans can never 'seep back' that which we have previously lost

Cetaceans, such as dolphins and whales can has unihemispheric sleep, meaning they will sleep with half a brain at a time. One half of the brain must always stay awake to maintain life-necessary movement in the aquatic environment. But the other half of the brain will fall into the most beautiful NREM sleep. Deep, powerful rhythmic, and slow brainwaves will drench the entirety of one cerebral hemisphere, yet the other half of the cerebrum will be bristling with frenetic, fast brainwave activity, fully awake

Place an organism under conditions of severe famine, and foraging for food will supersede sleep

Individuals who are deliberately fasting will sleep less as the brain is tricked into thinking that food has suddenly become scarce

The true pattern of biphasic sleep is one consisting of a longer bout of continuous sleep at night, followed by a shorter midafternoon nap

The practice of natural biphasic sleep, and a healthy diet, appear to be the keys to a long-sustained life

The amount of time we spend asleep is markedly shorter than all other primates (eight hours, relative to the ten to fifteen hours of sleep observed in all other primates), yet we have a disproportionate amount of REM sleep, the stage in which we dream. Between 20 and 25 percent of our sleep time is dedicated to REM sleep dreaming, compared to an average of only 9 percent across all other primates

The coolheaded ability to regulate our emotions each day depends on getting sufficient REM sleep night after night

An infant brain without sleep will be a brain ever underconstructed

Alcohol is one of the most powerful suppressors of REM sleep that we know of

Children need more sleep than their older siblings or parents. The circadian rhythm of a young child runs on an earlier, schedule. Children therefore become sleepy earlier and wake up earlier than their adult parents

No child needs caffeine

Sleep is more problematic and disordered in older adults. The effects of certain meditations more commonly taken by older adults, together with coexisting medical conditions, result in older adults being less able, on average, to obtain as much sleep, or as restorative a sleep, as young adults

That older adults simply need less sleep is a myth

Elderly individuals fail to connect their deterioration in health with their deterioration in sleep

The lower an older individual's sleep efficiency score, the higher their mortality risk, the worse their physical health, the more likely they are to suffer from depression, the less energy they report, and the lower their cognitive function, typified by forgetfulness. Any individual, no matter what age, will exhibit physical ailments, mental health instability, reduced alertness, and impaired memory if their sleep is chronically disrupted

The early-evening snooze will jettison precious sleep pressure, clearning away the sleepiness power of adenosine that has been steadily building throughout the day. Several hours later, when that older individual gets into bed and tries to fall asleep, they may not have enough sleep pressure to fall asleep quickly, or stay asleep as easily

Evening light suppresses the normal rise in melatonin, pushing an average adult's sleep onset time into the early-morning hours, preventing sleep at a reasonable hour

Sleep makes you live longer. It enhances your memory and makes you more creative. It makes you look more attractive. It keeps you slim and lowers food cravings. It protects you from cancer and dementia. It wards off colds and the flu. It lowers your risk of heart attacks and stroke, not to mention diabetes. You'll even feel happier, less depressed, and less anxious

No one type of sleep is more essential than another. Losing out on any one of these types of sleep will cause brain impairment

Sleep has proven itself time and again as a memory aid: both before learning, to prepare your brain for initially making new memories, and after learning, to cement those memories and prevent forgetting

Practice does not make perfect. It is practice, followed by a night of sleep, that leads to perfection

If you don't snooze, you lose

Post-performance sleep accelerates physical recovery from common inflammation, stimulates muscle repair, and helps restock cellular energy in the form of glucose and glycogen

Millions of individuals unwittingly spend years of their life in a sub-optimal state of psychological and physiological functioning, never maximizing their potential of mind or body due to their blind persistence in sleeping too little

After sixteen hours of being awake, the brain begins to fail. Humans need more than seven hours of sleep each night to maintain cognitive performance

Three full nights of recovery sleep are insufficient to restore performance back to normal levels after a week of short sleeping. The human mind cannot accurately sense how slee-deprived it is when sleep deprived

Vehicle accidents caused by drowsy driving exceed those caused by alcohol and drugs combined. Drowsy driving alone is worse than driving drunk

The amygdala—a key hot spot for triggering strong emotions such as anger and rage, and linked to the fight-or-flight response—showed well over a 60 percent amplification in emotional reactivity in the participants who were sleep-deprived

The under-slept brain swings excessively to both extremes of emotional valence, positive and negative

Insufficient sleep has also been linked to aggression, bullying, and behavioral problems in children across a range of ages

Equally problematic issues arise from extreme swings in positive mood. Hypersensitivity to pleasurable experiences can lead to sensation-seeking, risk-taking, and addiction. Sleep disturbance is a recognized hallmark associated with addictive substance use

'The best bridge between despair and hope is a good night's sleep.' - E. Joseph Cossman

A lack of sleep is fast becoming recognized as a key lifestyle factor determining whether or not you will develop Alzheimer's disease

Sleep disturbance precedes the onset of Alzheimer's disease by several years, suggesting that it may be an early-warning sign of the condition, or even a contributor to it

Wakefulness is low-level brain damage, while sleep is neurological sanitation

Without sufficient sleep, amyloid plaques build up in the brain, especially in deep-sleep-generating regions, attacking and degrading them. The loss of deep NREM sleep caused by this assault therefore lessens the ability to remove amyloid from the brain at night, resulting in greater amyloid deposition. More amyloid, less deep sleep, less deep sleep, more amyloid

Getting too little sleep across the adult life span will significantly raise your risk of developing Alzheimer's disease

By improving someone's sleep, we should be able to reduce their risk of developing Alzheimer's disease—or at least delay its onset

Prioritizing sleep across the life span is clearly becoming a significant factor for lowering Alzheimer's disease risk

'Sleep is the third pillar of good health, alongside diet and exercise.'

Sleep is more than a pillar; it is the foundation on which the other two health bastions sit

Every major system, tissue, and organ of your body suffers when sleep becomes short

The shorter your sleep, the shorter your life

Adults forty-five years or older who sleep fewer than six hours a night are 200 percent more likely to have a heart attack or stroke during their lifetime

The less you sleep, the more you are likely to eat

Sleeping less than sever or eight hours a night will increase your probability of gaining weight, being overweight, or being obese, and significantly increases your likelihood of developing type 2 diabetes

Leptin signals a sense of feeling full. When circulating levels of leptin are high, your appetite is blunted and you don't feel like eating. Ghrelin, in contrast, triggers a strong sensation of hunger. When ghrelin levels increase, so, too, does your desire to eat

Inadequate sleep decreased concentrations of the satiety-signaling hormone leptin and increased levels of the hunger-instigating hormone ghrelin

Getting enough sleep will help you control body weight

When you are not getting enough sleep, the body becomes especially stringy about giving up fat. Instead, muscle mass is depleted while fat is retained

Short sleep will increase hunger and appetite, compromise impulse control within the brain, increase food consumption, decrease feelings of food satisfaction after eating, and prevent effective weight loss when dieting

Men suffering from sleep disorders, especially sleep apnea associated with snoring, have significantly lower levels of testosterone than those of similar age and backgrounds but who do not suffer from a sleep condition

Males with low testosterone often feel tired and fatigued throughout the day. They find it difficult to concentrate on work tasks, as testosterone has a sharpening effect on the brain's ability to focus

Poor sleep quality increases the risk of cancer development and, if cancer is established, provides a virulent fertilizer for its rapid and more rampant growth

Journaling your waking thoughts, feelings, and concerns has a proven mental health benefit, and the same appears true of your dreams

Facial expressions represent one of the most important signals in our environment. They communicate the emotional state and intent of an individual and, if we interpret them correctly, influence our behavior in return

Better REM-sleep quality at night provided superior comprehension of the social world the next day

With the absence of such emotional acuity, normally gifted by the re-tuning skills of REM sleep at night, the sleep-deprived participants slipped into a default of fear bias, believing even gentle- or somewhat friendly looking faces were menacing. The outside world had become a more threatening and aversive place when the brain lacked REM sleep

REM sleep and the act of dreaming is for intelligent information processing that inspires creativity and promotes problem solving

If we feed a waking brain with the individual ingredients of a problem, novel connections and problem solutions should preferentially emerge after time spent in the REM dreaming state, relative to an equivalent amount of deliberative time spent awake. The content of people's dreams, above and beyond simply having REM sleep, should determine the success of those hyper-associative problem-solving benefits

It is both the act of dreaming and the associated content of those dreams that determine creative success

'A problem difficult at night is resolved in the morning after the committee of sleep has worked on it.' - John Steinbeck

The content of one's dreams determines problem-solving success

Participants who slept and reported dreaming of elements of the maze, and themes around experiences clearly related to it, showed almost ten times more improvement in their task performance upon awakening than those who slept just as much, and also dreamed, but did not dream of maze-related experiences

REM sleep, and the act of dreaming, takes that which we have learned in one experience setting and seeks to apply it to others stored in memory

Lucid dreaming occurs at the moment when an individual becomes aware that he or she is dreaming

The two most common triggers of chronic insomnia are psychological: 1. emotional concerns, or worry, and 2. emotional distress, or anxiety

Emotions make us do things, as the name suggests. They motivate our remarkable achievements, incite us to try again when we fail, keep us safe from potential harm, urge us to accomplish rewarding and beneficial outcomes, and compel us to cultivate social and romantic relationships. Emotions in appropriate amounts make life worth living

Emotionless, you will simply exist, rather than live

Physiological processes within the mammalian body can only operate within a remarkably narrow temperature range. Dropping below or above these life-defining thermal thresholds is a fast track to death

When core body temperature drops, mammals respond by increasing their metabolic rate. Burning energy releases heat to warm the brain and body to get them back above the critical thermal threshold so as to avert death

Many individuals in the modern world only give themselves 5 to 6.5 hours of sleep opportunity, which normally means they will only obtain around 4.5 to 6 hours of actual sleep

When food becomes scarce, sleep becomes scarce, as animals try to stay awake longer to forage

Five key factors have powerfully changed how much and how well we sleep: 1. constant electric light as well as LED light, 2. regularized temperature, 3. caffeine, 4. alcohol, and 5. a legacy of punching time cards

Artifical evening light, even that of modest strength, or lux, will fool your suprachiasmatic nucleus into believing the sun has not yet set. The brake on melatonin, which should otherwise have been released with the timing of dusk, remains forcefully applied within your brain under duress of electric light

A recent survey of over fifteen hundred American adults found that 90 percent of individuals regularly used some form of portable electronic device sixty minutes or less before bedtime. It has a very real impact on your melatonin release, and thus ability to time the onset of sleep

Compared to reading a printed book, reading on an iPad suppressed melatonin release by over 50 percent at night

Create lowered, dim light in the rooms where you spennd your evening hours. Avoid powerful overhead lights

Wear yellow-tinted glasses indoors in the afternoon and evening to help filter out the most harmful blue light that suppresses melatonin

Maintaining complete darkness throughout the night is equally critical. Blackout curtains

Install software on your computers, phones, and tablet devices that gradually de-saturate the harmful blue LED light as evening progresses

Alcohol suppresses REM sleep. When the body metabolizes alcohol it produces by-product chemicals called aldehydes and ketones. The aldehydes in particular will block the brain's ability to generate REM sleep

Memories remain perilously vulnerable to any disruption of sleep even up to three nights after learning

To successfully initiate sleep, your core temperature needs to decrease by 2 to 3 degrees Fahrenheit. You will always find it easier to fall asleep in a room that is too cold than too hot

A bedroom temperature of around 65 degrees Fahrenheit is ideal for the sleep of most people, assuming standard bedding and clothing

Hot baths prior to bed can also induce 10 to 15 percent more deep NREM sleep in healthy adults

Participants artificially wrenched from sleep will suffer a spike in blood pressure and a shock acceleration in heart rate caused by an explosive burst of activity from the fight-or-flight branch of the nervous system

If alarming your heart were not bad enough, using the snooze feature means that you will repeatedly inflict that cardiovascular assault again and again within a short span of time

Waking up at the same time of day, every day, no matter if it is the week or the weekend is a good recommendation for maintaining a stable sleep schedule if you are having difficulty with sleep

Sleeping pills do not provide natural sleep, can damage health, and increase the risk of life-threatening diseases

No past or current sleeping medications on the market induce natural sleep

Ambien-induced sleep caused a 50 percent weakening of the brain-cell connections originally formed during learning

Although users of sleeping pills may fall alseep nominally faster at night, they should expect to wake up with few(er) memories of yesterday

Individuals using prescription sleep medications are significantly more likely to die and to develop cancer than those who do not

Natural sleep is one of the most powerful boosters of the immune system, helping ward off infections

It is possible that medication-induced sleep does not provide the same restorative immune benefits as natural sleep

Reducing caffeine and alcohol intake, removing screen technology from the bedroom, and having a cool bedroom

1. Establish a regular bedtime and wake-up time, even on weekends

2. Go to bed only when sleepy and avoid sleeping on the couch early/mid-evenings

3. Never lie awake in bed for a significant time period; rather, get out of bed and do something quiet and relaxing until the urge to sleep returns

4. Avoid daytime napping if you are having difficulty sleeping at night

5. Reduce anxiety-provoking thoughts and worries by learning to mentally decelerate before bed

6. Remove visible clockfaces from view in the bedroom, preventing clock-watching anxiety at night

Sleep and physical exertion have a bidirectional relationship

Progressively increased levels of physical activity in healthy males results in a corresponding progressive increase in the amount of deep NREM sleep they obtain on subsequent nights

In younger, healthy adults, exercise frequently increases total sleep time, especially deep NREM sleep

It is clear that a sedentary life is one that does not help with sound sleep, and all of us should try to engage in some degree of regular exercise to help maintain not only the fitness of our bodies but also the quantity and quality of our sleep

Try not to exercise right before bed. Body temperature can remain high for an hour or two after physical exertioin

Best to get your workout in at least two to three hours before turning the bedside light out

Severe caloric restriction, such as reducing food intake to just 800 calories a day for one month, makes it harder to fall asleep normally, and decreases the amount of deep NREM sleep at night

Eating a high-carbohydrate, low-fat diet for two days decreases the amount of deep NREM sleep at night, but increases the amount of REM sleep dreaming, relative to a two-day diet low in carbohydrates and high in fat

Scientific evidence suggests that you should avoid going to bed too full or too hungry, and shy away from diets that are excessively biased toward carbohydrates, especially sugar

Shorter sleep amounts predict lower work rate and slow completion speed of basic tasks

Naps as short as twenty-six minutes in length still offered a 34 percent improvement in task performance and more than a 50 percent increase in overall alertness

REM sleep is what stands between rationality and insanity

It is the lack of REM sleep—that critical stage occurring in the final hours of sleep that we strip from our children and teenagers by way of early school start times—that creates the difference between a stable and unstable mental state

No matter what the age, the longer a child slept, the more intellectually gifted they were

Individuals who were sleeping longer obtained better grades across the board

One practice known to convert a healthy new habit into a permanent way of life is exposure to your own data

When it comes to the quantified self, it's the old adage of 'seeing is believing' that ensures longer-term adherence to healthy habits

Prevention is far more efficient than treatment, and costs far less in the long run

12 tip for healthy sleep

1. Stick to a sleep schedule

2. Exercise is great, but not too late in the day

3. Avoid caffeine and nicotine

4. Avoid alcoholic drinks before bed

5. Avoid large meals and beverages late at night

6. If possible, avoid medicines that delay or disrupt your sleep

7. Don't take naps after 3 p.m.

8. Relax before bed

9. Take a hot bath before bed

10. Dark bedroom, cool bedroom, gadget-free bedroom

11. Have the right sunlight exposure

12. Don't lie in bed awake