You wake up. You hear the refrigerator click on and you hear the television in the other room. You can smell the fabric softener on the bedsheets and feel the warmth of the blanket on your body. However, you can’t move a muscle. You tell your eyelids to open but they do not respond. Your heart begins to race as you sense a presence enter the room... Is this the opening scene from a cheesy horror flick? No, this is actually a very real condition experienced by thousands of people every day, yet it still leaves sleep researchers scratching their heads as to why we experience this.

Sleep Paralysis:

When sleep studies have been conducted for sleep paralysis, researchers noted that episodes occurred when patient’s sleep was interrupted during REM cycles. Patients became consciously aware of surroundings due to partial awakening, but were still stuck somewhere in the deepest part of sleep that keeps your muscles at bay so you can't physically act out your dreams. Thus, a patient is awake, but unable to move.

Many times during sleep paralysis, hallucinations can occur making you feel that there is someone in the room, but you can not move to protect yourself. It is also often reported that there is a sense of pressure on the suffer's chest. This will then cause the intense anxiety that is normally associated with sleep paralysis. At this time, there is no clearly defined process on how to stop sleep paralysis.

Historically, reports attributed this condition to a type of demon, called an incubus, whom would sit on their victim's chest while attmpting to steal their soul. 

Demon on ChestCredit: Public Domain


There are two different classes of sleep paralysis:

  • Isolated Sleep Paralysis (ISP)- More often than not, this condition happens to a person infrequently, maybe even as little as once in a lifetime. Normally an episode of ISP only lasts for about a minute, and then the person either comes awake and fully functioning or back to sleep. 

  • Recurrent Sleep Paralysis (RISP)- people who are plagued with RISP may have episodes every so often to a few times a night. One of the main differences between ISP and RISP is that the latter can last up to an hour. During these long periods of RISP, a person may feel as if their spirits have been removed from their bodies.


While the concept of sleep paralysis could be a major plot point in a horror flick, doctors don’t consider this sleep disorder to be harmful or dangerous. Is the feeling the disorder brings about weird or scary? Sure, but as terrifying as this experience may be, we do not have to worry about suffering physical harm from it.