You wake in the dead of night and look around the familiar setting of your bedroom. Everything initially looks normal, but something feels slightly different. You sense that you are not alone. Then out of the corner of your eye, you see an eerie shadow. You try to move, try to sit up and get a better view, but you can’t – you’re completely paralysed.
While this may sound like something out of a horror story, what I have just described is a personal description of the phenomenon known as sleep paralysis, experienced in some form or another by up to 8% of the population.
What is sleep paralysis?
Sleep paralysis is a condition defined by the temporary inability to move or talk whilst falling asleep or waking up. It can often be accompanied by terrifying and bizarre visual or auditory hallucinations and usually passes in a few seconds or minutes.
Sufferers describe some or all of the following symptoms:
- Difficulty taking deep breaths
- Inability to move or speak
- Sensed presence
- Intense fear
Sleep paralysis has been long been associated with evil spirits, demons and supernatural entities. Symptoms have been described by many different cultures and throughout history and it may be the superstitions entwined in cultures which act as a catalyst for the hallucinations experienced. For example, many African cultures attribute voodoo magic as it’s cause, with the attacks being due to zombies coming to visit in the night. Whilst in the Caribbean sleep paralysis, also known as ‘kokma’, is believed to be caused by the souls of dead unbaptized babies who come and strangle victims in their sleep.
Image Credit: Pixabay
Causes of sleep paralysis
Sleep paralysis is a recognised condition caused by the body not moving through the stages of sleep properly. There are two types of sleep paralysis; one occurs when your falling asleep, called predormital sleep paralysis and the other when you’re waking up, called postdormital sleep paralysis.
Predormital sleep paralysis occurs when your body relaxes as you start to enter into a sleep cycle but your mind still remains conscious and is aware that you can’t move or speak. It is often associated with the sleep condition narcolepsy, which results from the brain’s inability to regulate normal sleep wake cycles.
Postdormital sleep paralysis is much more common and occurs when your body wakes from a state of REM (rapid eye movement) sleep. During REM sleep, the most vivid dreams occur and your body is paralysed by your brain to prevent you from acting these dreams out. Sleep paralysis can occur when your brain awakes from and incomplete cycle of REM sleep, whilst your body is still paralysed.
Whilst there is no known definitive cause of sleep paralysis, it has been linked to: stress, certain medications, depression, substance abuse and recently a gene which helps regulates our bodies’ sense of time. It has been associated with other sleep conditions and has also found to be more common in psychiatric patients, being experienced by up to 32% of them (and, interestingly, 28% of students).
Prevention and treatment
Luckily, although terrifying sleep paralysis isn’t actually dangerous and most of the time there is no need for any treatment, although in particular cases low doses of anti-depressants may be prescribed. Some tips for avoiding it include; sleeping on your side, establishing a regular sleep cycle, regular exercise and avoiding eating, drinking or smoking just before bed.