Imagine awaking from sleep only to find you are unable to move. It may feel as though your body is trapped between sleep and wakefulness.
This is sleep paralysis.
Per WebMD, "Sleep researchers conclude that, in most cases, sleep paralysis is simply a sign that your body is not moving smoothly through the stages of sleep."
Many who suffer from the affliction have described nightmare sleep paralysis stories, such as the feeling of waking up in a state of fright, compressed and surrounded by a kind of unease often associated with the supernatural.
While sleep paralysis has long been shrouded in mystery, scientific gains have helped researchers to understand more about this phenomenon, why it occurs and how to deal with it. As is the case with many strange sleep disorders, sleep paralysis continues to be extensively researched. Understanding the science - and how to control it - may help you stop worrying that Beelzebub is stalking your bedside.
You don't remain completely paralyzed during an entire sleep cycle. Otherwise, no one would ever "toss and turn."
However, according to a study conducted at the University of Toronto, when you enter the rapid eye movement (REM) stage of sleep, your brain releases signals to still the skeletal muscles in your body. These muscles remain "switched off" until you move to the next sleep stage.
As Live Science attests: "the muscles are unable to move so that the person won't be able to act out dreams with their body." Sleep paralysis typically occurs when your mind wakes from REM sleep, but your body doesn't respond as quickly. However, it is possible for sleep paralysis to occur while falling asleep.
Clinical psychologist and sleep researcher Dr. Michael J. Breus writes, "Episodes of sleep paralysis can last for a few seconds or as long as a few minutes."
However, according to the American Sleep Association, sleep paralysis may last for hours in some cases. For these individuals, the experience can be panic-inducing. One example is the case of a woman who began suffering from anxiety, exhaustion, and sleep paralysis after a traumatizing car accident. Her case was also accompanied hypnopompic hallucinations (which occur as you emerge from sleep).
In 1781, Henry Fuseli unveiled a painting of a woman sleeping with an incubus on her chest. The work, named The Nightmare, has long been associated with sleep paralysis.
A number of cultures around the world have used the myth of the incubus/succubus or an equivalent tale to explain the feeling of being sat upon or crushed during an episode of sleep paralysis. In some cultures, all types of sleep paralysis are blamed on these spirits.
Sleep paralysis is a mercurial beast. It can be a symptom of narcolepsy, but this is not always the case. Some studies show a much higher rate of sleep paralysis among psychiatric patients, while other resources suggest it commonly occurs as a result of sleep problems arisen from jet lag (although such incidents are usually isolated and are not associated with lifelong sleep paralysis).
Trauma, anxiety, and depression increase the likelihood of sleep paralysis; genetics are also contributing factors. The issue has also been linked to PTSD. The many possible causes necessitate individual study for each patient with the disorder.