Sam Smith claims fame isn't always a "nice thing".

He said: "You think you're going to have loads of money and that everything's going to be great. And that everyone's going to love you.

And you're never going to be sad. And you're going to be performing all the time. And you're going to be invincible.

"But going through it, becoming famous? It isn't necessarily a nice thing."

The 22-year-old singer - who picked up four Grammy Awards earlier this month - added there have been times when he has doubted whether he wants to continue living his life in the spotlight.

He told The Observer newspaper: "It's weird. Something you want so badly all your life happens. And then you think, 'Oh s**t'.

"I thought, 'Do I want this? Maybe I've misunderstood what this job entails.'"

And Sam is doing his best "not to go mental" because of his new-found fame.

He said: "I've spent as much energy this past year trying not to go mental as I have plugging my record. You have to. It's like your body's trying to float away from you. And you're hanging on for dear life."