Ask the Pharmacist

Q)  I am fascinated by the different stages of sleep, in particular REM sleep.  What can you tell me about it?

A)  Rapid eye movement (REM) sleep is one of the four stages of sleep that our bodies cycle through continuously throughout the night.  It is the stage of sleep that is closest to being awake, in that, unlike the other stages of sleep, our brains are very active.  Despite this high level of activity, engaging in REM sleep is vital to our long-term health as well as feeling rested and ready to tackle the next day’s challenges. To better understand REM sleep, we should do a quick review of the various stages of sleep.

There are 4 stages of sleep;  

  • non-REM stage 1
  • non-REM stage 2
  • non-REM stage 3
  • REM

Non-REM stage 1 occurs when you first fall asleep, lasts for only a few minutes, and is considered to be a light sleep. 

In the second stage of non-REM, your body slows down as breathing and heart rates decrease, brain waves slow and body temperature drops. 

The third stage of non-REM sleep is also known as deep sleep.  It is during this cycle that your body essentially repairs itself.  Muscle and bone injuries are healed, your immune system is tuned up and many hormones are released. 

It is after this stage that REM sleep begins.  In an ideal situation we cycle through these 4 stages every 90 to 110 minutes throughout the night with a typical adult repeating the entire cycle four to six times if they are allowing themselves the recommended 7 to 9 hours of sleep we should be aiming for. 

REM sleep is very different than the other stages of sleep.  It accounts for approximately 20-25% of our total sleep and just over 50% of an infant’s, not surprising given its role in brain development.  In REM sleep, the majority of our vivid dreaming occurs.  It is here that our heart rate, breathing and brain activity all increase while at the same time your brain paralyzes the muscles in your arms and legs so that you are unable to act out your dreams.  REM sleep is critical to our emotional health, our ability to think and possibly even to our longevity if new research is proven to be correct. 

It is also during REM sleep that memories are consolidated.  New learned skills and information are committed to memory and where muscle memory, so critical in performance type activities, occurs.  There’s also evidence that your brain divorces memories from the emotions connected to them during this stage.  This is why when we go to bed upset about some event in our life, many of us wake up feeling somewhat better about it.

Good sleep truly is a form of therapy.  Dreaming might be related to this benefit as well.  Some researchers think dreams help with the processing of painful experiences.  Others think that dreams are simply an unintended by-product of all the neurological processes that are going on in the background.  REM sleep also makes us smarter since the this is when connections between our brain cells that were formed during the day’s activities are strengthened and integrated into existing stored information.  It is this process that allows us to sometimes wake up with novel solutions to problems that were plaguing us the day before.  In short, REM sleep makes us more creative.   

Given these important functions, it is not surprising to learn that there are negative ramifications in not getting enough REM sleep. 

  • Reduced coping skills:  research suggests that a lack of REM sleep may reduce a person’s ability to differentiate between threatening and non-threatening stimuli and respond accordingly. 
  • Migraine: Fragmented sleep may increase a person’s risk of experiencing migraine in the immediately following days. 
  • Obesity: Some studies associate the quantity and quality of REM sleep with an increased risk of obesity. 
  • Neurological Disorders- fragmented REM sleep has been associated with a number of these ranging from mild forgetfulness to Parkinson’s and dementia. 

There is also some evidence that REM sleep is linked to overall mortality.  A 2020 study of over 4,000 adults found that each 5% decrease in REM sleep was linked with a 13% chance of dying from any cause over the next 20 years.  While it’s true that sleep deprivation in general shortens life spans, it appears that poor REM sleep has a greater impact than any of the other stages.   

Unfortunately, there is no way to specifically improve your REM sleep.  Instead, focus on the tenets of what helps most of us sleep better.  These include: 

  • Waking up and going to bed at the same time every day.  This helps your brain make your time asleep more efficient and restful. 
  • Have a consistent eating schedule and do not eat too late in the day. 
  • Exercise regularly
  • Try to get some morning sunlight to help cement your Circadian rhythms
  • Avoid blue light from phones and computers at night
  • Allow yourself a “wind-down” time before going to bed
  • Avoid alcohol late at night.  Alcohol markedly impairs REM sleep as the process by which your body breaks down alcohol affects your sleep cycles
  • Allow enough time for you to sleep.  Cutting yourself short can really impact the REM stage since its longest periods tend to occur at the end of the night
  • Avoid evening stimulants such as caffeine
  • Follow the 25 minute rule –  if you have been in bed for 25 minutes without sleeping (or going back to sleep), get up and engage in a quiet activity
  • Reserve your bed for sleeping and sex.  It’s not a place for work or watching screens. 

Following these rules is hard, especially since many of us were able to ignore them for decades and sleep just fine.  However, there is plenty of evidence to suggest that obeying them can greatly improve your sleep and therefore your health.   

For more information about this or any other health related questions, contact your pharmacist.