Billie Eilish has "made friends" with having Tourette's syndrome

She said: "It's not like I like it, but I feel like it's part of me. I have made friends with it. And so now, I'm pretty confident in it. When I'm moving around, I'm not ticcing at all. When I'm riding my horse, I'm not ticcing. When I'm moving and thinking and focusing, when I'm singing [I'm not ticcing]."

But the 'bad guy' hitmaker admitted she gets "incredibly offended" when people laugh at her tics or think she's making the movements on purpose.

Speaking on 'My Next Guest Needs To Introduction', she told host David Letterman: "It's really weird. I haven't talked about it like at all. The most common way that people react is they laugh because they think I'm trying to be funny. They think I'm going like [imitates one of her tics] as, like, a funny move.

"So they go like 'Ha!' and I am always left incredibly offended by that or they [turn their head behind them] and go 'What?' And then I go, 'I have Tourette's'.

Billie was fascinated to learn other musicians also have the condition.

She said: "What's funny is so many people have it that you would never know. A couple artists came forward and said, 'I've actually always had Tourette's,' and I'm not going to out them because they don't want to talk about it, but that was actually really interesting to me. I was like 'You do?! What?' "

The 'Ocean Eyes' hitmaker finds her tics "very exhausting" but admitted people rarely notice them when they are in conversation with her.

She said: "I actually really love answering questions about it because it's very, very interesting and I am incredibly confused by it and I don't get it.

"I never don't tic at all, because the main tics that I do constantly all day long are like are like, I wiggle my ear back and forth, and raise my eyebrow, and click my jaw and do that, and like flex my arm here, and flex this arm, and flex these muscles.

"These are things you would never notice if you're just having a conversation with me. But for me, they're very exhausting."