Billie Eilish is sharing what it's like for her to live with Tourette syndrome.
The singer, 20, spoke about the subject during the season four premiere of My Guest Needs No Introduction With David Letterman, which premiered on Netflix May 20.
According to Cedars Sinai, "Tourette syndrome is a neurological disorder that causes people to make unintended sounds, words and body movements, called tics."
After experiencing a tic, the "bad guy" artist told host David Letterman,"If you film me for long enough, you're going to see lots of tics."
Eilish said people don't always understand when it happens in the moment. "The most common way that people react is they laugh because they think I'm like trying to be funny," she said. "They think I'm going like [imitates tic] as like a funny move. So they go like, 'Ha.' And I'm always left incredibly offended by that. Or they go like, 'What?' And then I go, 'I have Tourette's.'"
However, the seven-time Grammy winner noted that she's "very happy talking about it" and thanked Letterman for asking.
"I actually really love answering questions about it because it's very, very interesting," she said, "and I am incredibly confused by it and I don't get it."
Eilish explained she was diagnosed with Tourette syndrome when she was 11 and had small tics as a child.
"I never, like, don't tic at all because the main tics that I do constantly all day long are, like, I wiggle my ear back and forth and, like, raise my eyebrow and click my jaw and do that and flex my arm here and flex this arm and flex these muscles," she said. "These are things you would never notice, like, if you're just having a conversation with me. But for me, they're very exhausting."
Although, the "Happier Than Ever" star said she doesn't tic when she's performing or focusing on singing or songwriting. "When I'm moving around, I'm not even ticcing at all, you know?" she added. "When I'm riding my horse, I'm not ticcing."
At one point, Letterman asked if Eilish would ever "damn" her Tourette syndrome symptoms. "Yes. Now, I don't," she replied. "It's not like I like it, but I feel like it's a part of me. I have made friends with it. So now, I'm pretty, like, confident in it."