To help parse fact from fiction, some experts explain exactly how sleep paralysis in the Netflix show The Haunting of Hill House works, reports Bustle.

“Sleep paralysis often rears its ugly head when you’re just starting to fall asleep or at the moment you’re waking,” Erin Berman, a lifestyle and wellness expert at Nectar Sleep, tells Bustle. Berman says it’s common to experience an intense crushing pressure on your chest during sleep paralysis, making it difficult to breathe. She says most people experiencing sleep paralysis can open their eyes, but they can’t move their bodies. But the most terrifying part of sleep paralysis? Hallucinations like the Bent Neck Lady are actually common.