The 22-year-old singer was left unable to talk after being struck down with laryngitis just a week before the release of her new album 21.
According to the Daily Star, when she sought professional help, she was quickly advised to stop smoking.
'I've had laryngitis and I couldn't speak for six days last week,' she said. 'I didn't think I'd be able to sing at the album launch. I literally had a chalkboard around my neck.
'I went to see a therapist, not for my head, for my voice. He told me to lay off the cigarettes. It's not just the fags, I've had to give up milk, tomatoes, sweets, sucking mints.'