Sam Smith had a panic attack after realising how successful he'd become in the US.

The 22-year-old singer admits he struggled to get his head around how well known he'd become stateside, but is adamant he'll always remain true to his routes.

Speaking to Digital Spy, he said: ''The whole American thing completely wasn't planned. I had a panic attack the other day. I was thinking, 'F**k'.

''The UK is so important to me. It's everything - it's my home. I love America but it's so important for me to be here and be an artist and be well known here.''

Meanwhile, the 'Stay With Me' hitmaker has met his fair share of famous people after shooting into the limelight two years ago, but admits he was shocked when Kim Kardashian West, 33, recognised him at an event.

He explained: ''I met Kim Kardashian West the other week and she knew who I was! I walked in the room and she was like, 'I should text Kanye saying you're here, he showed me your music'.

''It's really hard to digest. Also, I don't think you should digest stuff like that.''

However, the hunky star is adamant he won't let his new-found fame go to his head.

He said: ''I think I'd lose my head! I'm just trying to pay attention to the shows. The bigger the shows get, that's when it gets overwhelming.''