Despite being one of the world`s most successful female singers, the 25-year-old star admits she is sometimes overcome with nerves and says her stage fright was the reason behind a tearful breakdown at the Radio 1 Teen Awards in London over the weekend.

Speaking about her highly charged performance of `Firework` at the event, Katy told the Daily Star newspaper: "I was emotional before I sang `Firework.` I got chills and butterflies - it`s a huge adrenaline rush. All the hairs stick up on my body and sometimes I don`t even have to sing because the crowds sing it louder.

"I still feel nervous performing to crowds. It`s not that I don`t feel ready but I worry that they`ll rush the stage as they`re all screaming my name or I feel like a wanna yack!"

This is not the first time Katy has admitted her nerves, and she had previously admitted to being particularly self-conscious.

She explained: "Even the most confident people still have their moments of insecurity. And even though I may come across as loud and bubbly and brimming with confidence, I can be a shy girl too."
sections: Celebrities