[A Unified Theory of Healthcare - How it all links together] Sleep paralysis: a phenomenon more common than we think!

A Unified Theory of Healthcare - How it all links together. Sleep paralysis: a phenomenon more common than we think.

- an article by our senior mentor Michael; part of the UTOH series. In this blog series, we look at current common approaches to managing pain and illness in our healthcare system. With the example of sleep deprivation, we attempt to show how some factors still misunderstood and often ignored can lead to worsening health and poorer outcomes in some patients. We also look into ways to improve rehabilitation of such patients by stepping away from some of our current healthcare beliefs. Find the other articles from this series right here.


Humans have been fascinated by sleep for thousands of years. Greek mythology had gods that represented thoughts and emotions, personifying the concepts of life, death, war, thunder, as well as sleep and dreams. The gods of sleep and dreams had names you may recognise from popular TV shows and movies, the god Hypnos for example, represented Sleep, and Hypnos was the son of Nyx, the Goddess of the Night. In the Iliad (an ancient Greek poem), Zeus feared her immense powers more than any other deity – which highlights the respect and fascination the Greeks had for the process of sleep. Nyx became the inspiration for other deities such as Dionysus Nyktelios, which gave rise to the term nocturnal.

The God of death – Thanatos (‘I am inevitable’ - ring a bell to any Marvel fans?), is a son of Nyx – a merciless, terrifying and hated character. Beating Thanatos in battle literally meant cheating death, and Hypnos (God of sleep) was the brother of Thanatos. He lived in a cave surrounded by plants that induced sleep, next to the river Lethe – a water all intruders had to be careful not to fall into lest they become forgetful and absent mined for the rest of their lives.

There were also the black winged demons known as the Oneiroi, the sons of Nyx and the Daemons of dreams. They were responsible for carrying prophetic messages in dreams, in addition to the experience of Deja Vu. For the movie buffs out there, one Oneiroi was named Morpheus, who took on a human form to interact with the dreamer. The other demons were Phantasos (meaning fantasy), taking on the form of inanimate objects and elements, and Phobetor (the one who scares the dreamer), personifying nightmares and taking on the form of animals, birds, serpents etc.

This little history lesson leads us to todays topic of sleep paralysis.




Sleep paralysis has been a known phenomenon for thousands of years, but recent medical history (alongside the development of sleep as a specialised field of study) has been able to provide detailed physiological insight on a this terrifying phenomena we have previously had to use our imagination and story telling skills to describe.

Sleep paralysis is estimated to affect approximately 8% of the general population, around 700 million people. As diagnostics is primarily based on subjective history taking for the most part, people will be able to identify a few episodes where they experienced it, as it is usually triggered by periods of stress with poor quality sleep hygiene. It is therefore a completely natural phenomenon, but long term sufferers have more frequent episodes and it is these individuals we will focus on for this article.   

Sleep paralysis primarily manifests through atonia (the inability to move), shortly after falling asleep or while waking up. During an episode, the person feels awake and is aware of the lack of muscle control. Interestingly, approx. 75% of sufferers involve hallucinations that are different from a ‘normal’ dream, or even a lucid dream (the feeling of being in control of your dreams).

These  hallucinations will usually occur when falling asleep (hypnagogic hallucination) or when upon waking (hypnopompic hallucination). An estimated 75% of sleep paralysis episodes involve hallucinations that are distinct from typical dreams.

"An estimated 10% of people have more recurrent or bothersome episodes that make sleep paralysis especially distressing. As a result, they may develop negative thoughts about going to bed, reducing time allotted for sleep or provoking anxiety around bedtime that makes it harder to fall asleep. Sleep deprivation can lead to excessive sleepiness and numerous other consequences for a person’s overall health."


The hallucinations usually fall within 3 different categories, although a wide range of experiences have been reported. Yours truly, for example, has been diagnosed with sleep paralysis as a form of sleep parasomnia (a category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep). I experience auditory hallucinations, and will often hear people walking in my hall way or trying to open my door, scratching my tent when I am out camping etc, coupled with visual hallucinations (usually seeing dark figures in corners or straight up zombie-looking monsters) and finally, the most ridiculous of all, haptic hallucinations (a sensory impression such as sight, touch, sound, smell, or taste that has no basis in external stimulation). So a typical night terror episode for me will usually be something like hearing someone trying to break down my door, then seeing them break into my room, walk up to my bed and bite my face – all without me being able to move.

The face biting thing is a bit odd, but it definitely feels like what my brain imagines being bitten in the face would feel like, and that lies at the core of a haptic imagination.

Hallucinations during sleep paralysis fall into three categories:

  • Intruder hallucinations, which involve the perception of a dangerous person or presence in the room.
  • Chest pressure hallucinations, also called incubus hallucinations, that can incite a feeling of suffocation. These frequently occur along with intruder hallucinations.
  • Vestibular-motor (V-M) hallucinations, which can include feelings of movement (such as flying) or out-of-body sensations.

Atonia is often perceived as highly distressing by the dreamer, 90% of episodes are therefore usually associated with fear, however 10% can have pleasant or even euphoric hallucinations – such as flying, or ‘being in love’, or any number of delightfully pleasant experiences we can have, interestingly, these experiences appear to be linked to culture.

An average episode of sleep paralysis lasts around 5-6 minutes, but they can stretch from a few seconds up to 20 minutes. An episode can end on its own, often by the dreamer being so restless or distressed they eventually wake themselves up. For couples, often the partner recognizes symptoms associated with the dreamer having an episode and wakes them up.

The cause of sleep paralysis is technically unknown, there isn’t any one single factor we can point to as the cause. However, researchers are confident that we have identified multiple factors that can bring on an episode. Preexisting sleep disorders are most strongly correlated, for example sleep apnoea and, a bit randomly, nighttime leg cramps! Those who suffer with insomnia and excessive daytime sleepiness, shift workers, people with jet lag.

Mental health also plays a role, anxiety, panic disorders are more likely to suffer it, PTSD, as well as deep rooted issues PTSD

Insomnia symptoms like having a hard time falling asleep and excessive daytime sleepiness have been found to be associated with sleep paralysis. People whose circadian rhythms are not aligned with their local day-night cycle, such as people with jet lag and shift workers, may also be at higher risk of sleep paralysis. Excessive drug or alcohol abuse suppresses REM sleep, and this can return if one stops taking the stimulants which can trigger paralysis. Some studies have found that people who show traits of imaginativeness and disassociating9 from their immediate environment, such as with daydreaming, are more likely to experience sleep paralysis. There may be a link as well between sleep paralysis and vivid nightmares and/or lucid dreaming.


Should you / your patient be worried?

If you have sleep paralysis you shouldn’t be worried. It is a benign condition and usually, with some simple steps, doesn’t require invasive treatment to resolve.

However, an estimated 10% of people have more recurrent or bothersome episodes that make sleep paralysis especially distressing. As a result, they may develop negative thoughts about going to bed, reducing time allotted for sleep or provoking anxiety around bedtime that makes it harder to fall asleep. Sleep deprivation can lead to excessive sleepiness and numerous other consequences for a person’s overall health.



What can you do about it? How can you advise patients?

The first step is to get it diagnosed accurately, consider talking to a doctor and get a referral to a sleep clinic depending on how long you have had symptoms for. There are also several special sleep clinics available for a private appointment should you wish to consider that,

A first step in treating sleep paralysis is to talk with a doctor in order to identify and address underlying problems that may be contributing to the frequency or severity of episodes. For example, this could involve treatment for narcolepsy or steps to better manage sleep apnea.

Overall, there is limited scientific evidence about the optimal treatment for sleep paralysis. Many people don’t know that the condition is relatively common and thus see themselves as crazy or shameful after episodes. As a result, even just the acknowledgement and normalization of their symptoms by a doctor can be beneficial.

Because of the connection between sleep paralysis and general sleeping problems, improving sleep hygiene is a common focus in preventing sleep paralysis. Sleep hygiene refers to a person’s bedroom setting and daily habits that influence sleep quality.

Examples of healthy sleep tips that can contribute to better sleep hygiene and more consistent nightly rest include:

  • Following the same schedule for going to bed and waking up every day, including on weekends
  • Keeping a set pre-bed routine that helps you get comfortable and relaxed
  • Outfitting your bed with the best mattress and best pillow for your nee
  • Setting up your bedroom to have limited intrusion from light or noise
  • Setting the temperature in your room nice and low, around 17-19 degrees C is good
  • Reducing consumption of alcohol and caffeine, especially in the evening.
  • Putting away electronic devices, including cell phones, for at least a half-hour before bed.

You can work on your sleep hygiene thought cognitive behavioural therapy, which has techniques that can address many of the issues related to sleep paralysis. Improving sleep hygiene is frequently incorporated into cognitive behavioural therapy by addressing several other factors such as anxiety of depression. A specific form of CBT has been developed for sleep paralysis, but more research is needed to validate its effectiveness.


Find the other articles from this series right here.


See also:

Persistent Pain / Chronic Pain pack

This pack is aimed at physiotherapists and healthcare professionals as well as students working or soon to be working with patients with persistent pain. It will introduce you to the topic of persistent pain and provide you with an insight into the complexities of managing this type of patient. We will discuss treatment approaches and available resources in addition to different frameworks and pathways you can use in your own clinical practice.