Lewis Capaldi has told fans he has Tourette's Syndrome (TS), speaking about its day-to-day effects in an Instagram Live video.
The 25-year-old explained that due to his twitches, people mistakenly think he takes drugs before concerts.
TS is a condition that "causes a person to make involuntary sounds and movements called tics", according to the NHS.
"I have Tourette's, I've always had it, apparently," the Scottish singer said.
He recently mentioned on stage that he has the condition, explaining why his shoulders sometimes twitch.
"I do the shoulder twitch quite a lot. And you see underneath every TikTok and stuff, people are like, 'why is he twitching?', which is fine. Curiosity is fine."
"Do you think before performing [in front of] 20,000 people, as an anxious person, I'm going to take a big line of cocaine? Never going to happen."
What is Tourette's Syndrome?
TS is neurological condition that causes a person to make involuntary sounds and movements called tics
It usually starts during childhood, but symptoms normally improve after several years and sometimes go away completely
Tics can be brought on by anything at all but stress and anxiety are common triggers
Most people with TS are not significantly affected by their tics or behaviours, and so do not need medication. However, there are options available which can help control the tics if they are causing problems
More than 300,000 children and adults are living with TS in the UK
There has been a positive reaction to Lewis's honesty from fans with the condition.
"It's good that someone of that calibre is able to feel comfortable enough to say, 'Yeah, I've got Tourette's syndrome'," Holly Ann Maria tells Radio 1 Newsbeat.
"I think it's really important because it shows that yes, he has a debilitating disability. However, he is still very talented."
The 23-year-old from Essex says Lewis's attitude is "really quite refreshing".
"A lot of people don't like to talk about controversial topics, but he literally talks about anything and everything and doesn't care."
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Lewis also spoke about how he has had Botox in his shoulder to try to limit the tics.
"It's a new thing, I haven't really learned much about it - I'm learning. I had Botox on my shoulder to stop it moving. It worked for a bit."
He told fans that he didn't think it was a big deal, but that when he got the diagnosis, it made sense to him.
Earlier this year, Billie Eilish spoke about having the condition, telling American host David Letterman that the condition can be "exhausting".