Considering we spend approximately one-third of our lives sleeping, it is good to understand the science behind sleep. Many people notice that when they go through certain phases in their lives, their sleep habits tend to change. Becoming a new parent definitely has an impact on your sleep habits! Getting older and entering perimenopause and then menopause can have a big impact on your sleep patterns as well. Sometimes, it doesn't even take a particular phase in our lives for us to have difficulty sleeping.
More than 50 million Americans struggle with one of the 100 sleep disorders out there, and many more have trouble sleeping on a fairly regular basis. Sleep is actually quite remarkable, and it is fascinating to understand the processes that the body goes through during the night. We have come a long way from the belief that sleep was a passive process, as they previously thought before the 1950s. Here are 10 things you need to know about the science behind sleep.
10 There Are 2 Phases Of Sleep: REM Sleep & Non-REM Sleep
There are two distinct phases of sleep: rapid eye movement (REM) sleep and non-REM sleep. Non-REM sleep has three phases of its own, as you slowly descend into the deepest part of your sleep, which is REM sleep. The first stage that we enter in Stage 1 non-REM sleep, where we are changing over from wakefulness to sleep, and our breathing slows and our muscles begin to relax. As we enter the second phase of non-REM sleep, your breathing slows even more, muscles relax further, and your eye movements stop.
Now you are descending into deeper sleep when you enter the third stage of non-REM sleep, and this is the period of deep sleep that your body needs in order to feel refreshed in the morning. Your muscles are now completely relaxed, your brain waves are slow, and it is likely difficult to wake you. Finally, you enter REM sleep, usually about 90 minutes after first falling asleep. Your eyes move rapidly, your brain waves are almost that of wakefulness, and this is the stage where you dream the most.
9 Your Circadian Rhythm Is Your Internal Clock
There are two main control systems in your body when it comes to sleep and wakefulness: your Circadian rhythm and sleep-wake homeostasis. These two biological mechanisms work together to let your body know when it needs sleep and helps to prepare the body for sleep. Circadian rhythms are synchronized to environmental stimuli like lightness and darkness, and they help your body to recognize the cues for sleep time.
The sleep-wake homeostasis tracks your body's need for sleep, making you feel tired when you need to rest, and waking you in the morning when your body has had enough rest. Certain elements can affect your sleep-wake homeostasis, including medical conditions, stress, sleep environment, and what you eat and drink.
8 Sleep Deprivation Leads To Health Problems
It has been widely proven that a continual lack of sleep can lead to a range of health problems, including impairment to your attention and focus, heart disease, heart attack, diabetes, high blood pressure, and stroke. It can diminish your sex drive, cause mood fluctuations, and make you much more prone to accidents.
The National Sleep Foundation estimates that sleep deprivation causes 100,000 crashes, 71,000 injuries, 1,550 deaths every year. That is a shockingly high number of incidents that are attributed to sleep deprivation, proving again the huge importance sleep plays in our health and well-being.
7 Everyone Dreams
Do you ever have those nights where you wake up and feel like you didn't dream at all? Even though it may feel as though you didn't dream, in fact, everyone dreams at night. You spend approximately 2 hours every night dreaming, and the majority of your dreams will take place while you are in REM sleep.
People that are under stress or who struggle with mental disorders are often more prone to frightening or stressful dreams. Scientists aren't completely sure of the purpose of dreams, but most speculate that dreams are how we process our emotions and thoughts from the day.
6 The Hypothalamus Is The Control Center For Sleep
The hypothalamus is a small peanut-sized structured deep within the brain that contains a group of nerve cells that are responsible for regulating sleep and arousal. Within the hypothalamus, there is a large cluster of cells called the suprachiasmatic nucleus, or SCN, which recognizes light stimuli from your eyes and helps to control your body's rhythms.
People who have had damage to the SCN often sleep erratically throughout the day, as they are unable to regulate their body's rhythms. The SCN also sends signals to the pineal gland, which in turn releases the hormone melatonin, which helps to inform your body that it is time to sleep.
5 Age Affects Your Circadian Rhythm
Our Circadian rhythm is the 24-hour internal clock that ticks away inside us and let us know when it is time to sleep. For the majority of our lives, this internal clock maintains a fairly consistent rhythm. However, as we age, the rhythm tends to get more sporadic, and our sleep is affected by it.
Older people tend to sleep less during the night, waking earlier in the morning than they used to. They may also find that they begin to tire earlier in the evenings and even lose some of their cognitive functioning. There are ways to get the Circadian rhythm back on track, however, by working in some aerobic activity throughout the day and sticking to a regular sleep routine.
4 There Are More Than 100 Different Sleep Disorders
Although we usually only hear about a few common sleep disorders, such as insomnia, sleep apnea, and restless legs syndrome, there are actually about 100 different sleep disorders! Some of the less common sleep disorders include such ones as Upper Airways Resistance Syndrome (UARS), where the airway is narrowed during sleep, making breathing difficult.
Other less-common sleep disorders include REM Sleep Behavior Disorder, Circadian Rhythm Disorder, Narcolepsy, and Periodic Limb Movement Disorder. There are many different sleep disorders, and if you suspect that you or someone you care about is struggling with a sleep disorder, seek advice from a medical professional.
3 Sleep Apnea Affects 20 Million Americans
Sleep Apnea is one of the most common sleep disorders, and it currently affects over 20 million Americans. Sleep apnea occurs when breathing is interrupted during sleep, and people who suffer from sleep apnea often stop breathing for periods of time while they sleep.
There are two forms of sleep apnea: Obstructive Sleep Apnea (OSA) and Central Sleep Apnea (CSA). OSA is when there is a blockage in the airway, usually it is the soft tissue at the back of the throat that collapses during sleep. OSA can cause daytime sleepiness, snoring, and general fatigue. CSA is when the brain simply forgets to tell the body to breathe. People with CSA may wake and gasp for air, and they report frequent waking during the night.
2 Less Sleep = Bigger Appetite
The link between sleep deprivation and increased appetite has been explained by sleep experts. When we are deprived of sleep, our leptin levels decrease in our bodies. Leptin is a hunger-regulating hormone, so when these levels fall, our appetite increases to make up for the dip.
So, if you find that you are frequenting the fridge during a night of sleeplessness, this could be why. It is not that your body is actually in need to nourishment, but more that your leptin levels have fallen and your hunger-regulating hormone is tricking you into thinking that you are, in fact, hungry.
1 12% Of People Dream Entirely In Black & White
While everybody dreams, not everyone dreams in the same way. While most people report dreaming in color, there are some who see their dreams in black and white only. According to sleep experts, there tends to be a correlation between their exposure to color television or black and white television in childhood.
A study published by the NCBI explained that those under 25 years of age reported dreaming primarily in color. However, people who were 55 years or older, and grew up with primarily a black and white television, dreamt in monochromatic hues most of the time. Regardless of their exposure to television, 12% of people dream regularly in black and white.