Billie Eilish has a lot of "weird sleep issues".
The 18-year-old singer takes "forever" to drop off at night, and when she does finally fall asleep, she's plagued with severe nightmares and has even woken up unable to move in the past.
She said: "I went to sleep on a plane sitting up the other day for, like, the first time ever. I've had sleep paralysis three times. I have a lot of weird sleep issues. I have these terrifying dreams and stuff. Sleep paralysis, night terrors...
"It takes me forever to fall asleep. I don't understand how people can fall asleep [straight away] - that's so weird to me."
The 'Bury A Friend' hitmaker admitted her bad dreams can impact on her whole day, and it's been particularly tough lately thanks to a recurring nightmare.
She told heat magazine: "It's weird because normally the nightmares I have don't make me wake up. Lately, I've had a couple that do, but normally the dream is the whole night - so the whole night is terrifying. They can really mess me up, so the whole day is off sometimes.
"I'll have a dream that really screws with my head and makes me kind of just feel... I don't know what it is but it makes me feel uncomfortable all day. I've had the same nightmare for like two months in a row. Horrible.
"And it affects me day-to-day. It affects how I act and all that."
When she's having a nightmare, Billie is very much aware that she's asleep and she can even "control" what's happening in them, which she finds "torturing".
She said: "In my dreams, I always know they are dreams. So I can kind of do things in them, knowing that they are dreams. So if I die in my dreams, I normally come back to life. It's like a video game almost.
"I'm kind of living through my dreams. They're lucid dreams, that's what it is. And I create, I can kind of control things in my dreams. It's very torturing."
But one consolation for the 'Bad Guy' singer is that her nocturnal disturbances have influenced her music.
She said: "They have given me a couple of ideas for my songs. I probably wouldn't have made ['Bury a Friend'] the way it is if I hadn't had sleep paralysis and horrible nightmares and night terrors and hadn't been able to sleep and all that stuff. So, that's a good point, a good way of looking at it."