Sleep Paralysis is a very frightening experience that can sometimes happen during sleep.
Here it goes.
You are lying in bed in that special transitional state between sleep and wakefulness. You may be about to fall asleep, or you might have woken up in the middle of the night and are then trying to fall asleep again, or you may be just about to fully wake up in the morning.
In either case, what actually happens is that your mind is fully aware of being awake but your body is unable to move. It doesn’t matter how hard you try but no muscle will eventually respond to your orders. Obviously you might feel frightened and you will most likely have several thoughts crossing your mind, such as: What’s happening to me? Am I paralysed? I want to call for help but I’m not even able to open my mouth and utter a single word!
This temporary paralysis can last from a few seconds up to even 10-15 minutes. After a while you will eventually regain control of your own body but this represents quite a shocking experience that won’t easily be forgotten.
Another disquieting feature of sleep paralysis is the fact that most of the times it is accompanied by hallucinatory phenomena, adding to the experienced sense of fear.
The most common kind of hallucinatory phenomenon reported, is the perception of a threatening presence in the room, as if there were an intruder. Sometimes this presence is more intensively perceived through the senses than just merely detected: it could even be seen, heard or smelled. Those who have gone through this kind of unsettling experience can also report they were being touched or even attacked by this ‘alleged’ presence as though a weight was pressing them down on the chest, leaving them unable to move or preventing them from sitting up.
It is indeed quite a disturbing experience.
Another particular but less common hallucinatory phenomenon that can accompany Sleep Paralysis, is an Out-of-Body experience (OBE).
The person is paralysed in bed but has the feeling that their own soul is leaving the body, flying and floating in the room or even outside of the house, watching the body from an external perspective. Contrary to the intruder hallucination, this kind of experience is usually associated to very positive feelings.
Sleep paralysis seems to be caused by a REM-sleep intrusion into wakefulness. REM-sleep is a stage of sleep where our muscles are almost totally atonic.
It is rare yet it can occur if the transition between REM-sleep and wakefulness is quick and sudden; as a matter of fact, the brain maintains the body in an atonic state ‘by mistake’.
Some authors suggest that the reason why hallucinations tend to accompany sleep paralysis lies in the activation of the so called ‘vigilance system’. The potential threat of the sleep paralysis experience activates this system, whose aim is to scan and monitor the environment in search of potential dangers. In this singular and ambiguous situation, the brain may very easily misinterpret environmental signals (Cheyne, 2002; Cheyne, 2007).
Experiencing Sleep Paralysis once in a while shouldn’t worry you excessively.
Sleep deprivation, having an irregular sleep-wake rhythm or going through a stressful period can well trigger this phenomenon.
Furthermore, sleep paralysis is a frequent symptom of narcolepsy.
If this phenomenon is recurrent then consulting a sleep specialist is warmly recommended.