Ever woken up unable to move or speak, feeling an eerie presence in your room? You might have experienced sleep paralysis—a temporary inability to control your body while transitioning between sleep and wakefulness.

During an episode, some feel a crushing weight on their chest, see shadowy figures, or struggle to open their eyes. Though usually brief, these moments can be terrifying.

While sleep paralysis is typically harmless, you should seek medical help if:

• It happens frequently
• Fear of it disrupts your sleep
• You experience excessive daytime sleepiness or muscle weakness, signs of narcolepsy

Watch: Real People Share Their Creepy Sleep Paralysis Nightmares

What Causes Sleep Paralysis?

Sleep paralysis occurs when the REM (Rapid Eye Movement) stage overlaps with wakefulness, leaving the mind awake while the body remains immobilized. It usually happens during transitions between sleep and wakefulness.