You wake up out of a hazy sleep and you're completely paralyzed.

There's something heavy sitting on your chest that you can't see and an eerie sense that someone's in the room with you.

Your heart pounds, everything spirals, becoming more and more surreal as you scream silently inside. Is this something from a horror movie

scene or from real life? Welcome back to savvy psychologist. I'm your host

Dr. Jade Wu. Every week I'll help you meet

life's challenges with evidence-based research, a sympathetic ear, and zero

judgment. Today we look at the freaky phenomenon of sleep paralysis, an experience that has inspired

ghost stories and alien abduction conspiracies. Fortunately, there's a scientific explanation for why it happens and also ways to prevent it.

Different cultures have explained this frightening experience called sleep paralysis in various different ways.

In Brazilian folklore, a crown with long fingernails lurks on the roof and trampels on

sleeper's chests.

In Japanese mythology, vengeful spirits come to suffocate their enemies while they sleep.

For Canadian Eskimos, it's the spells of shamans that paralyze a sleeper while giving them vivid

hallucinations. And in contemporary American culture, sleep paralysis has

taken on the mythology of alien abductions.

Sleepers wake up unable to move, seeing or feeling the presence of aliens or at least shadows

in the room while experiencing zapping sensations and a feeling of suffocation.

But it turns out that all of these symptoms describe sleep paralysis, a sleep disorder or a

symptom of a sleep disorder or a symptom of a sleep disorder that temporarily alters a person's

mobility, perception, thinking, and emotional state during that weird transition stage between sleeping and waking.

Sleep paralysis is surprisingly common.

Almost 8% of the general population has experienced it at least once. But if you're a

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