Sleep is characterized by three features:
1) It is a fleeting reversible state (the person can be awakened)
2) It is a behavioral need (some people need more sleep than others)
3) It is a perceptual detachment from the environment (one is not aware of their surroundings whilst asleep)

It is believed to be habitual, as we all have different sleep requirements, patterns, habits or cycles. As we go further into deep sleep, the brain gradually becomes less responsive to visual, auditory and other environmental stimuli during the transition from wake to sleep.

Sleep is required by the body to rejuvenate both mind and body; experts believe that the mind organizes its thoughts whilst the person is sleeping. Likewise, your muscles take the chance to rebuild its fibers to prepare for another day of work!

Sleep Debt

Everyone has to sleep at some point during the day. When work demands push us beyond the limit and we go sleepless for more than 24 hours, our sleep deficit builds up, and our reflexes and mental functions begin to slow down. This sleep deficit builds up throughout the week, causing us to become less productive at work, irritable, depressed and sleepy. The negative effects of our sleep debt start to surface in everyday activities like driving and studying.

Many companies today encourage their executives to clock 100-hour work weeks. They also applaud the road warrior who lives out of a suitcase in multiple time zones, and promotes the employee who takes a red-eye flight to make an 9 am meeting. This kind of corporate behavior is the antithesis of high performance. It endangers employees and puts other people’s lives at risk.
There are neurobiological functions that affect sleep duration and quality, as well as individual performance. When these functions fall out of alignment because of sleep deprivation, people then operate at a far lower level of performance than they would if they were well rested.

Unsurprisingly, many repay their sleep debt by sleeping on weekends. Such ‘crash and burn’ methods are extremely draining on the body and are not the solution in the long term. With decreased sleep, higher order cognitive tasks like reasoning and important decision making are hampered; speed and accuracy are also affected. In driving simulations, accidents increase progressively as total sleep duration is decreased to seven, five, and three hours per night over a week.

The 5 stages of Sleep
There are a total of 5 stages of sleep that you go through while asleep. You are not aware of these changes while you’re asleep and each stage serves a different function. Also, there are different sensations whilst at different stages, and you can’t control which stage occurs at what time. It varies from person to person and might also be affected by the environment.

Full Consciousness ” This is the point where you’re fully awake and going about your daily lives. It’s at this point that our wakefulness system is at its peak point during the day.

Stage 1 Sleep ” Every one of us has gone through Stage 1 of sleep, though not many are aware of it. Do you remember the time when you were in a boring lecture, or in a movie theatre watching a really ‘draggy’ movie The drowsy sensation, also known as ‘zoning out’ is the perfect way to describe this stage of sleep.

At this point, you enter Stage 1 of sleep and exhibit slightly lower frequency brain waves known as Alpha brain waves and some Theta brain waves. Your body relaxes, respiration and heart rate drops slightly, and our mind tends to drift into an altered state of relaxation where it simply feels good to be there! Your head starts to nod off as you lose muscle control…

Stage 2 Sleep ” During Stage 2 of sleep, we experience patterns of brain waves called sleep spindles. These are sudden bursts of brain activity which scientists believe are attempts by the brain to shut certain portions of itself down. Technically, however, your mind is still very active during sleep, helping you organize your thoughts and processing events that occurred during the day. During Stage 1 and 2 of sleep, you can still be easily awoken. This is the premise of a power nap.

Stage 3 & 4 Sleep ” During Stage 3 & 4 of sleep, our brain waves are at their lowest frequency known as Delta brain waves.
It is during these 2 stages that we are officially “asleep”, and it is known as deep sleep. Our blood pressure, heart and respiration rate dip to their lowest point in the day. Our blood vessels dilate and carry blood to muscles and organs for repair and recovery. Athletes depend on these stages to repair worn and fatigued muscles.

Stage 5 Sleep ” Stage 5 sleep is the most fascinating segment of your snooze as science has not been able to ascertain its true purpose. It is known as Rapid Eye Movement (REM) Sleep. When people were awoken during this stage, they reported that they were actually in a dream moments before! It is believed that most of our dreaming is done during this REM sleep stage.

Surprisingly, our brain waves do not lower in frequency during this stage. In fact, they rise rapidly and are similar to brain waves exhibited when we are wide awake. If you think about it, it makes sense ” while we are dreaming, our mind perceives the situation as a very real and vivid one. Don’t you remember the time when you woke up, certain that you had seen or experienced something so real it bothered you for the rest of the day

That should give you a good idea of the stages of your sleep. Check out my other articles, where I will talk about numerous other sleep disorders and their solutions!

Now that you have a better understand of sleep stages, the final piece of the puzzle is sleep cycles. Instead of progressively going through each stage and waking up after reaching stage 5, the body instead goes from stage 1 to 5 multiple times in a specific order. This is known as a complete sleep cycle.

Now, the way we travel through our sleep stages is as follows:

1, 2, 3, 4, 3, 2, REM, 2, 3, 4, 3, 2, REM, 2, 3, 4, 3, 2, REM, 2, 3, 4, 3, 2, REM, 2, 3, 4, 3, 2, REM…

Do you see a pattern? It repeats every 2, 3, 4, 3, 2, REM!
Each cycle takes about 60 ??” 100 min for an average person.

Here are a few points you might be interested in.
•    The 1st period of deep sleep is the longest, and it gets shorter and shorter as time goes on. Toward the end, deep sleep almost becomes non ??” existent.

•    The 1st period of REM sleep is the shortest, and it gets longer and longer as time goes on. Toward the end, it becomes the longest.

Sleep also becomes lighter and lighter as the night progresses. We do not spend the same amount of time in each stage of sleep.

Now, you might be wondering to yourself, how does this all relate to insomnia and snoring? Well, you must first understand how you sleep, before you can correctly diagnose your problems. This should build upon my previous article on the stages of sleep. Check out my other articles, where I will talk about numerous other sleep disorders and their solutions!