We have all experienced the effects of a poor night’s sleep. You feel groggy and slower; you might feel the dreaded brain fog. When you close your eyes, do you ever wonder what happens when you sleep

Most people readily accept sleep is a vital aspect of your health, but there are so many aspects of our day to day life that interrupt our sleep. 

I was curious to learn exactly why sleep is important to your health, what happens when you sleep, and finally how to recognize if a lack of sleep might be something more dangerous. I asked Dr. Kirsch if he could explain sleep.

Dr. Douglas B. Kirsch, a board-certified Neurologist and Sleep Specialist, is the medical director of sleep medicine and sleep laboratories for Sleep Medicine at Atrium Health in Charlotte.

Why is sleep important?

Sleep is an essential part of life and is part of the triad of healthy living which also includes a healthy diet and exercise. We need adequate sleep time and quality to perform optimally every day and be our best self. Deprived of sleep, the function of mind and body diminish, mood disregulates, cognition begins to fail.

What happens to the brain and body as we sleep?

Contrary to popular opinion, the brain is fairly active at times during sleep. We go through cycles of sleep of about 90-120 minutes, so about 4-5 cycles per night. The cycles include two primary sleep types, both NREM and REM, each of which has an important role in brain function, cognition, and memory formation. We tend to have more vivid dreaming during REM sleep, though dreaming can also occur during NREM sleep.

Sleep Cycles

As opposed to the brain, the body is generally quiescent, with relaxed muscles, lower blood pressure, and slower heart rate. This allows our body to recover from the previous day and be ready to function well in the next day.

How can someone tell if they have healthy sleep?

Feeling rested and refreshed in the morning is often a sign of high-quality sleep of a sufficient amount. Either insufficient sleep or fragmented sleep will often affect daytime quality of life, mood, and function.

As well, feeling sleepy during the daytime can be a sign that there is a sleep problem. Though most of us have “low energy points” during the daytime after lunchtime and in the late afternoon, we should not be falling asleep at work or while driving a car.

Consumer monitors, such as a Fitbit, will provide some data about sleep quality, but that data may or may not adequately reflect the actual quality of your sleep. Use them optimally to assess how much opportunity you are giving yourself to sleep. Feeling unrefreshed in the morning occasionally is not necessarily the sign of a sleep disorder, but it is a signal to evaluate how much sleep you get and if there are signs of a sleep disorder. 

What happens to our health when we are sleep deprived?

People function poorly when either acutely deprived or chronically deprived of sleep. Our cognition and productivity slow, our metabolism and immune system work less well, and our mood becomes less well regulated. Our glucose levels become less well-controlled, making diabetes control worse. Recent research has suggested increased risk of dementia likely occurs with sleep deprivation.

What’s one thing someone can do to improve their sleep tonight?

Take enough time to sleep. The American Academy of Sleep Medicine recommendations suggest a minimum of 7 hours of sleep time per night, though many people (particularly kids and younger adults) need more than 7 hours to be healthy and feel their best. Try to keep your sleep on a stable schedule, getting up at nearly the same time every day, including weekends. Put down the phone/stop the electronics before bedtime.

When should you bring up poor sleep to your doctor?

Reasons to talk to your doctor may include: 

      • loud snoring
      • witnessed pauses in breathing during sleep
      • significant daytime sleepiness
      • significantly fragmented sleep
      • restless legs in the evening that is disruptive to your sleep or quality of life
      • sleep walking/abnormal movements during sleep.

Sleep is important to your health. Good sleep helps your brain and body functionally optimally and improves your mood. One of the easiest ways to sleep better is to put your phone away before you go to sleep.

If you think you might suffer from a sleep disorder, contact your primary care physician to discuss your symptoms or schedule an appointment with an American Board of Sleep Medicine doctor.

Calculate the Ideal Amount of Sleep