The most restorative sleep stage is Deep Sleep or Stage 3 NREM or Slow Wave Sleep, which is when your body repairs tissues, builds muscle and bones and strengthens your immune system.
REM Sleep is also vital and one of the most restorative sleep stages, as REM sleep is vital for cognitive functions like learning, memory and emotional processing, with a healthy balance of both being key for optimal health.
During NREM stage 3 sleep or deep sleep, your brain produces slow delta waves, your heart rate and breathing slow and your muscles also relax completely.
This is a restful part of sleep as it's when your body does it's most important physical restoration, growth and immune system support.
And it's very difficult to wake up from NREM stage 3 sleep, which leads to significant grogginess or sleep inertia if you're awakened.
During REM sleep, your brain activity increases, which is similar to being awake, dreaming occurs and your body also focuses energy on cognitive functions and it's essential for learning, emotional regulation and creativity and memory consolidation.
Deep sleep provides physical restoration to the body and REM sleep provides mental rejuvenation, and you need a healthy balance of both REM sleep and NREM stage 3 sleep, along with lighter sleep stages for truly restorative sleep and optimal health.
The signs of poor core sleep are persistent daytime impairment and physical or even emotional health issues.
Common signs of poor core sleep include daytime fatigue and drowsiness and a persistent feeling of being unrefreshed, exhausted or having a heavy urge to nap during the day.
Difficulty concentrating, trouble focusing, or brain fog and a reduced attention span.
Memory problems, like difficulty in learning new information, poor memory recall and trouble retaining information, mood changes like increased irritability, anxiety, mood swings, lower mood or heightened sensitivity to stress.
And reduced alertness and reduced reaction tine, like slower physical and mental responses to stimuli.
Other physical signs of poor core sleep are waking up feeling unrefreshed, and feeling tired immediately upon waking up, as though you did not sleep well, increased appetite and cravings, like strong cravings for high calorie foods, sugar or caffeine, weakened immune system, getting sick more often or having a slower recovery from illness and slower physical recovery and increased muscle soreness or slower healing after physical activity.
Even physical appearance changes like dark circles under your eyes or sallow skin and low energy levels and a general lack of having energy throughout the day.
Not getting enough sleep can also result in you experience microsleeps, which are brief and involuntary episodes of sleep that lasts from as little as a fraction of a second to around 30 seconds.
During a microsleep, your brain shuts down momentarily, and causes you to lose awareness, often without you even realizing it.
Microsleep is also a dangerous phenomenon, especially if you're performing tasks, such as operating machinery or driving, as you can also appear awake, with your head nodding and eyes open, but during a microsleep you are not processing information, which leads to accidents.
Causes of microsleep include sleep disorders, shift work, monotonous activities and even severe sleep deprivation.
The key characteristics of microsleeps are that the duration of the microsleeps are usually between 1 to 15 seconds or even a fraction of a second, although microsleeps can last as long as 30 seconds.
Microsleeps can occur with your eyes open and you looking awake, or with heavy eyelids, blank stares and even head nodding.
During the microsleeps, your brain waves slow down, also known as theta waves and your brain then stops processing external information.
Common causes of microsleeps occurring re a result of not getting enough sleep overtime, conditions like narcolepsy or sleep apnea, irregular work hours such as shift work that disrupt your natural sleep patterns and doing monotonous tasks like repetitive work or long drives.
Operating machinery or vehicles is dangerous when you experience microsleeps as it can cause severe accidents or even fatal accidents.
To prevent microsleeps, prioritize getting 7 to 9 hours of sleep and take breaks, when you're drowsy and if you have persistent sleepiness you should see a doctor.