Why do we sleep? What is its purpose? Sure, we feel tired and so we sleep; and then when we awake, we are usually rested.
But how does sleep allows us to become rested? The truth of the matter is that no one is still exactly sure, but a great deal is known about the features of normal sleep.
This is helpful because it provides a yardstick upon which to measure sleep patterns that are outside of normal indicating a sleep disorder.
To start with, sleep duration is important.
The average amount of time most people sleep is 7.
5 to 8 hours nightly.
However, the "normal" range can be anywhere from 4 hours a night to 10 hours a night.
Some people are "short-sleepers" and some "long-sleepers".
In order to best determine where your sleep patterns fall, try and remember how many hours of sleep you needed to feel rested when you were in your 20's.
By the time you are an adult, your duration of sleep needed remains the same throughout adulthood.
You may sleep 10 hours a night now (because you're snoring is disrupting your sleep) but your baseline requirements may only be 8 hours a night.
Sleep itself is divided into REM sleep (rapid eye movement) and NREM sleep (non-rapid eye movement).
These two alternative through the night and each REM-NREM alternation period is called a sleep cycle.
Most people have between 3 to 5 sleep cycles each night.
NREM sleep is also divided into 3 stages.
These include stage I or light sleep, stage II which is the most abundant NREM stage, and stage III which is deep sleep.
Deep sleep is more prevalent in the beginning of the night, and REM sleep is more prevalent in the second half of the night.
Generally, for an adult, NREM sleep makes up 75 percent of sleep and REM sleep should make up 25 percent.
Deep sleep in NREM sleep itself is approximately 25 percent of the night's sleep as well but declines slightly after age 60 to a lesser percentage.
Reduced amounts of deep sleep and REM sleep have the most significant effects on your sleep quality.
For children, the percentages are different.
As an infant REM sleep is 50 percent of sleep.
This figure declines during the first 2 years of life to 25 percent being the same as in adulthood.
Deep sleep in children remains a larger percentage of sleep until late adolescence.
To simplify sleep as best as possible, NREM sleep restores your body and makes you feel rested from the day's activities.
This is particularly true of deep sleep.
During this phase, your heart rate slows down, breathing slows as well, and even brain rhythms slow.
Think of NREM sleep as a recuperation phase.
Deep NREM sleep is more prevalent in the first part of the night as your body first seeks to restore its physical energy from the day.
REM sleep on the other hand is an active phase of sleep.
Heart rate and breathing are erratic, and brain waves are actively working.
This is the stage of sleep where most dreaming occurs.
While debate exists about its purpose, it seems REM sleep is important for our brains to work properly.
Think of REM sleep as a nighttime "backup" process where all the events of the day are loaded into memories, "anti-virus" scans are run, excess files are deleted, etc.
If one is REM sleep deprived, memory and attention are typically affected.
Regarding snoring, REM sleep is more important than NREM sleep.
During REM sleep, our muscles are "paralyzed" including our throat muscles around our airway.
The purpose of this paralysis is so that we do not physically act out our dreams during REM's active brain phase.
However, as the throat muscles relax during REM sleep, air passages can narrow and result in snoring or sleep apnea.
Just like a whistle, as the air opening narrows, noise is generated by the air flow.
As various sleep conditions including snoring and sleep apnea syndrome affect your sleep, the normal sleep architecture patterns are no longer "normal".
This can then result in many symptoms and physical signs.
In addition, because the body is not able to restore its function properly each day, it operates at less than optimal condition.
This can lead to infections, immune disorders, and many other problems.