What is Sleep?

“What is Sleep?”

This is a question that every civilization has tried to understand. We still don’t know all the answers, but we are getting closer.

Here are some things we do know.

Sleep is a necessary phase of life for all mammals.

It is essential for survival just like food and water and it is necessary for a healthy mind and body.

Sleep builds up our energy reserves so we can function at our best during our awake times and gives our brains the time to sort out the actions of our day. By doing this, we not only learn from our mistakes, but we also reinforce our positive experiences.

Sleep is also a time without stress that allows our body to repair itself, combat infections, and keep us on the road to optimal health.

Conversely, without adequate sleep, we would not be able to form or maintain the pathways in our brains that let us learn and create new memories, or to perform housekeeping duties to clean out the “spider webs.”We would find it incredibly hard to concentrate or respond quickly to questions or stimuli.

Lack of sleep has been the reason for major industrial disasters as well as vehicular and workplace accidents.

And believe it or not, without sleep, a person, or any mammal for that matter, will not live long.

People with extreme cases of insomnia die after about 18 months from lack of sleep.

Two systems control our sleep.

The timing of sleep is controlled by our circadian rhythms.

The duration and depth of sleep are controlled by our homeostatic control.

The Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle of a day. They keep us generally awake in the daytime and asleep in the dark of night.

Basically, circadian rhythms are our bodies’ internal clock.

Our circadian rhythms respond primarily to light and dark but also can react to changes in time zone, temperature, and metabolism.

Interestingly, researchers have discovered that circadian rhythms differ for different people and may possibly be genetically based.

So, some people are naturally night people and others are early morning risers.

This also means that if your parents were both night owls, you may naturally be a night owl and there may not be much you can do to change that.

Traveling from one time zone to another disrupts our circadian rhythms. You probably know it as jet lag.

So, when you fly from California to Boston, you lose 3 hours according to your body’s internal clock. When the alarm rings at 8 a.m., your internal clock will tell you to stay asleep because it is only 5 am in your body.

It usually takes a couple days to adjust to the new time.

The other sleep system, homeostatic control, refers to your body’s increased desire to sleep when you are awake and to wake up during sleep.

Homeostatic control regulates sleep intensity. Our drive for sleep increases the longer we are awake. And vice versa, our body’s drive to wake up increases the longer we are asleep.

This homeostatic sleep drive reaches its lowest level after a full night of good-quality sleep, and builds, almost constantly, while we are awake, pushing us to go back to sleep.

Our sleep drive is at its highest when we need sleep the most - such as when our body is fighting a sickness or a virus, or after a highly traumatic event. During these times, the body is telling you it needs to focus its energy on itself so go to sleep so it can do its crucial work.

We are learning more and more about the mystery of sleep every day.

But we still have so much more to learn.

What we know for sure right now is that sleep may be one of the most important things you do today and every day.