If you've ever seen an inexplicable figure, demon or alien by your bed shortly after waking up, you may very well have been in sleep paralysis.
Sleep paralysis can take place in your dream as well, when you're fully aware that you're dreaming and a demonic or fearsome creature appears before you, chasing after you, yet you cannot escape.
This unpleasant sensation is caused by a disruption of the REM phase of sleep, when the eyeballs are moving rapidly and the dreamed images appear more intensive and real.
However, during REM sleep, our body does not obey our commands, making us incapable of escaping that which frightens us. Sleep paralysis happens most often during nightmares, leading many to become fully convinced that they've seen a ghost, demon or extraterrestrial after they've awoken.
The mysterious figures and sensations that you cannot flee from sometimes look so real but are actually hallucinations. The brain makes them real and causes your subconscious to believe that they were truly there.
Our body acts differently in the different sleep phases. We are most relaxed in the REM phase because our subconscious makes us immobile, while our brain is on alert.
Every 4 out of 10 people share that they have fallen into a sate of sleep paralysis. Usually it happens during childhood or adolescence but does sometimes affect older people of both sexes.
Doctors have also discovered that the sleep pose is also a factor that provokes uncomfortable sensations while we're having a nightmare. If we sleep on our back with our arms crossed at our chest, we are essentially constricting our body, making our brain visualize troublesome images due to this discomfort.
If the sleep paralysis becomes chronic, you should immediately see a doctor because it is highly likely that something in your day-to-day life is causing this.