You wake up in the middle of the night unable to move. You are completely paralysed yet you sense a malevolent presence. A shadowy figure surges towards you. Suddenly you are struggling to breathe. The shadowy figure is sitting on your chest, strangling you. Then just as suddenly as it appeared, it is gone. Welcome to the weird world of sleep paralysis.
A Global Menace
Curious though it may seem, this is a worldwide phenomenon. From China’s gui ya shen, “ghost pressing on body”, to Vietnam’s bóng è, “held down by a shadow”, striking similarities are described in folktales from different cultures. The common theme is being attacked in bed by an evil being, which immobilises its victims by pressing them down, and sometimes causing the sensation of being choked or unable to breathe.
There are variations, of course. In Newfoundland, Canada, a foul-smelling old woman sits on her victim’s chest and strangles them. Her victims see strange shadows and glowing eyes before being attacked. Known as The Old Hag, there have been multiple academic papers written on the folktale and its connection to sleep paralysis.
The Science of Sleep Paralysis
In reality these experiences are examples of sleep paralysis, which affects roughly 8% of the population. Sleep paralysis can occur at two stages of the sleep cycle: while falling asleep (the hypnagogic or predormital form), and while waking up from sleep (the hypnopompic or post-dormital form). The latter is the most common and occurs when waking up prematurely from REM (rapid eye movement) sleep.
REM sleep is the period of sleep when dreams occur. During REM sleep our muscles enter a state known as atonia that immobilises them so we do not act out our dreams. If you wake up during REM sleep with your muscles still in an atonic state you are experiencing sleep paralysis, you cannot move or speak.
Some sufferers may feel pressure pushing them down, experience difficulty breathing, hallucinations, or overwhelming fear. Although there are several theories for these symptoms, as of yet there is no definitive explanation. Little wonder it is seen as a supernatural experience from which myths grow.
Likewise, there is no concrete explanation for what causes sleep paralysis. Exhaustion, stress, sleep deprivation, and an erratic sleep schedule are thought to be big contributors. Sleep studies have found that sleep paralysis among students is 28.3%, much higher than the 8% in the general population. The hazards of student life, constant stress and sleepless nights cramming for exams, may be putting them more at risk.
But do not worry, sleep paralysis is not physically harmful, despite its bad reputation in Southeast Asia. Over the years it has been common to point towards folktales as the cause of any unexplained death during sleep, conflating sleep paralysis with more deadly conditions. In the Philippines, which has seen many incidents of such deaths, it is attributed to “bangungot”, an old hag who sits on her victims suffocating them. Sound familiar?
These days bangungot is more of an umbrella term for unexplained deaths during sleep than a reference to a mythical old hag. The word itself made its way out of folklore and into the medical community as far back as 1917. The western world first got exposed to bangungot in the 1950s after a spate of deaths among young Filipino men working in Hawaii. Some point to this case as proof that bangungot is a uniquely Filipino malady and young Filipino men were the only victims despite being many kilometres from home.
More than 60 years later, doctors are still trying to unmask the medical cause of bangungot. While there are several suspects, sleep apnoea or Brugada syndrome for example, acute pancreatitis has gained some recognition as the most likely cause.
Making Sense Through Monsters
Although distressing, sleep paralysis speaks to a commonality of the human condition. No matter our race, religion or culture, we have a need to make sense of our experiences, and create an explanation that enters our folk culture, so we may sleep safe in the knowledge that we can make better sense of our world.