You wake up, but you can’t move. A high-pitched white noise is ringing in your ears and you’re finding it difficult to breathe. You try to sit up, but something evil is holding you down. And it won’t let go.
The description above sounds like a scene from a horror movie. But it isn’t. Instead, it explains a typical episode of sleep paralysis, a terrifying sleep condition which affects 1 in 4 of us at some point. So terrifying in fact, this universal phenomenon has taken on a supernatural dimension in countries and continents across the world. But what is sleep paralysis and what causes it?
The science behind sleep paralysis
According to the NHS, sleep paralysis is the temporary inability to move or speak that happens when you're waking up or falling asleep. While not harmful, episodes of paralysis can last anywhere between a few seconds to a couple of minutes, often leaving you frightened to go back to sleep.
Science says episodes of sleep paralysis happen when the brain cannot transition smoothly between sleep cycles. This occurs most frequently when the brain bypasses the non-REM sleep cycle, skipping straight to the rapid eye movement (REM) sleep cycle where the sleeping brain is most active and dreaming, but the muscles in the body are paralysed. It is during this stage where the sleeper will often wake up, finding themselves conscious but unable to move.
While the exact cause of sleep paralysis remains elusive, some studies suggest a link between sleep deprivation or irregular sleep schedules, such as jet lag or doing an all-nighter. Sleep paralysis is also linked to social anxiety, panic disorders and narcolepsy – a long term condition that causes people to fall asleep suddenly at inappropriate times.
With so much mystery surrounding the sleep disorder, it’s no wonder many societies still point to the supernatural or folklore to explain their experience with sleep paralysis. Here’s 5 of the spookiest sleep paralysis interpretations from around the world.
In Scandinavian folklore, sleep paralysis is said to be caused by a mare, a “female evil spirit thought to lie upon and suffocate sleepers.” According to such folklore, the spirit visits her victims in the night, taking the form of sand so she can sneak into their house through keyholes or cracks in the wall. The spirit then transforms into a young woman who then proceeds to terrorize her victim by sitting on their chest and smothering them. So terrifying where these episodes, we still talk about mares today. The word ‘nightmare’, which derives from the Old English word “mare”, was first coined to describe sleep paralysis, until it become a catch-all term for bad dreams.
In Mexico, “subirse el muerto” which roughly translates as “a dead body climbed on top of me” is a common expression used to describe the phenomenon of sleep paralysis. A study conducted in 2009 found that more than 90% of Mexican adolescents where familiar with the term, which originates from Mexican folklore, while more than 25% had experienced sleep paralysis themselves.
In Spain’s Catalonia region, the Pesanta is a monster that takes the form of an enormous black dog with paws of steel. Legend states that the Pesanta lives in the abandoned churches or ruins of Catalonia, only coming out at night to terrorize people in their homes while they sleep. Often people will wake up to the Pesanta sitting on their chest, suffocating them. When confronted, the monster escapes so fast you can only see its shadow.
In China and the Far East, episodes of sleep paralysis are known as “ghost oppression”, which stems from the ancient Chinese belief that an individual’s soul is vulnerable to evil spirits while they sleep. The first record of ghost oppression can be found in the earliest Chinese dictionary, dating back to the Eastern Han dynasty around AD30 to AD124.
Similarly, the interpretation in St Lucia is that sleep paralysis is caused by the spirits or ghosts of dead children who would try to strange you while you slept. Known as “kokma”, urban legend suggests such spirits are the souls of unbaptized or stillborn children.
Have you ever experienced sleep paralysis?