Have you ever experienced sleep paralysis, the condition where you may feel totally physically paralyzed either right before falling asleep or immediately upon waking up?
If you felt panicked after the experience, science is getting closer to understanding why.
A new study examines what exactly makes people feel distressed after a sleep paralysis episode, and shows that sensory experiences and innate "features" of the condition -- like feeling fear -- were linked with higher reports of distress.
The research, published in the journal Clinical Psychological Science, included 293 people who experienced sleep paralysis. The researchers asked them respond to emails after experiencing distress from sleep paralysis to identify the risk factors for that distress.
Researchers from the University of Waterloo found certain characteristics of sleep paralysis seemed to be particularly linked with panic after the fact. For example, experiencing the sensation that you are floating, or that you are having trouble breathing, was linked with higher distress.
The researchers also found that people who were more likely to associate their sleep paralysis with supernatural phenomena were more likely to experience distress, compared with more analytical people.
According to a 2011 review of studies in the journal Sleep Medicine Reviews, sleep paralysis is not totally uncommon. In fact, as many as 7.6 percent of the general population will experience it at least once in their lifetimes. The percentage is even higher for students and people with psychiatric disorders: 28.3 percent and 31.9 percent, respectively.
Sleep paralysis is not known to be harmful, but there are certain things you can do to reduce your risk of experiencing it, according to Stanford University, including minimizing stress, making sure to get a full night's rest, practicing good sleep hygiene and exercising regularly.