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An interesting study has shown that staying awake for 24 hours leads to a reduced hand-to-eye coordination comparable to having a blood alcohol content of 0.1.

Sleep is as important to our body as food and water, although most of us don’t consider it to be something so essential. As a consequence, we often suffer from insufficient sleep or disruptions to the sleep-wake cycle, which can cause the physiological state known as fatigue. Fatigue could be considered a disease of the modern man.

Besides these obvious consequences, lack of sleep can also affect the performance at work or at school. It could also be linked to an increased risk of emotional problems such as depression, mania, or miscellaneous drug addiction problems.

Normal regulation of sleep

A normal sleep cycle is regulated by several brain structures, external stimuli, and various hormones produced by the hypothalamus. One of the most important neurotransmitters involved is serotonin. There are three different processes controlled by our body during sleep regulation:

  • A homeostatic process: This is a body’s need for sleep. It is what is necessary for normal day activity.
  • A circadian process: This process controls how much time each part of sleep will last, as well as the propensity of these periods
  • An ultradian process: The purpose of this process is still not well known and remains uncertain.

There are two phases of sleep. A phase called REM (rapid eye movement) and a non- REM phase. Scientists believe that we dream in the first phase, but can rarely remember anything from that phase. Sleep proceeds in cycles of REM and non-REM phases. In humans, this cycle is approximately 90–110 minutes long. Each phase may have a distinct physiological function.

Sleep hormones

As mentioned above, some neurotransmitters or hormones are highly correlated with sleep and wake states. Melatonin levels are highest during the night, which is why it’s believed that this hormone may promote sleep. Another substance called Adenosine is gradually accumulated in the human brain during wakefulness, and decreased during sleep. It is considered to be a controller of wake/sleep periods.

Sleep and memory

Many scientists believe that memory depends on sleep; more sleep – better mnemonic abilities. Studies have shown that the REM phase of sleep helps the consolidation of memory, while non-REM sleep helps with the consolidation of declarative memories. Some disagree and say that saving memory directly into long-term memory is a slow process; they propose that cerebral input is first saved in a temporary memory store, and then encoded and transferred into long-term memory during sleep.  The fact is that, never mind which theory is correct it’s certain that sleep does have a role in maintaining and consolidating memory.

Symptoms of sleep deprivation in adults

Some of the most common symptoms of sleep deprivation in adults include:

  • Constant yawning
  • Sleepy grogginess (sleep inertia)
  • Poor concentration and mood changes (more irritable)
  • Exhaustion, fatigue, and lack of physical energy
  • The tendency to doze off when not active for a while
  • Grogginess when waking in the morning
  • The tendency to emotionally explode even at the mildest provocation
  • Moods constantly changing, resulting in pessimism, sadness, stress and anger


Symptoms of sleep deprivation in children

Sleep deprivation affects children in different ways then it does adults. No one really knows the reason why, but children tend to speed up, unlike adults which slow down, when deprived of sleep. Symptoms of sleep deprivation in children include:

  • Frequently losing temper 
  • Frequent and short daytime naps
  • Grunginess in the morning
  • Moodiness and irritability
  • Over-activity and hyperactive behavior

Causes of sleep deprivation

Common causes include:

Matter of personal choice: Many people simply don’t realize that they need sleep. Instead of regularly going to bed, they prefer socializing, watching television, etc.

Illness: Several diseases such as colds and tonsillitis can cause snoring, gagging and frequent waking, and have a direct effect on sleep by fragmentation. There is also Morvan's syndrome, which causes people to go without sleep for several months at a time.

Working night shift: One of the most common reasons why people don’t get enough sleep is work. People who do shift-work disrupt their sleep-wake cycles on a regular basis. 

Sleep disorder: There are several medical disorders capable of disrupting sleep on a regular basis. Some of the most common are sleep apnea, snoring, and periodic limb movement disorder.

Medications: It is no secret that several different medications can affect how we sleep. Some of the most common “sleep-disrupting” medications are antiepileptic drugs and medications used to treat the attention deficit disorder (ADD).

Bad habits: Drinking coffee or smoking cigarettes close to bedtime stimulates the nervous system and makes sleep less likely.

Lack of sleep and daytime performance

In you activities during the day, the amount of sleep you have behind you could be crucial; even an hour or two less than normal, could leave a great impact. Two-hour sleep loss can have a major impact including:

  • Reduced decision-making skills
  • Poorer memory
  • Reduced concentration
  • Reduced alertness
  • Shortened attention span
  • Slower than normal reaction time
  • Poorer judgment
  • Reduced awareness of the environment and situation
  • Reduced work efficiency

How much sleep is enough?

Different people need different numbers of sleep hours, depending on age, physical activity levels, general health and other individual factors.

In general:

  • Primary school children need about 9 to 10 hours
  • Teenagers need about nine to 10 hours also, because of specific lifestyle factors such as early school start times, etc.
  • Adults need less sleep then kids; it should be about 8 hours, depending on individual factors. 

Sleep suggestions

Here are some useful tips on getting more quality sleep hours!

  • Avoid taking sleeping pills. They can only worsen things.
  • Get up at the same time every morning, even after a bad night's sleep. 
  • Avoid worrying, watching TV, reading scary books, and doing other things in bed besides sleeping and sex.
  • Do not drink or eat anything caffeinated within six hours of bedtime.
  • Purposefully go to bed earlier each night as early as you can, but not before you feel sleepy
  • Don’t smoke or drink caffeinated beverages before bedtime
  • Use relaxation techniques to help you fall asleep quickly.
  • Seek professional assistance for sleep disorders such as snoring
  • Avoid alcohol. It's relaxing, but can lead to insomnia when it clears your system.
  • Spend time outdoors. People exposed to daylight or bright light therapy sleep better.