Michael Bublé says giving up cigarettes and alcohol almost destroyed his career.
The 43-year-old singer decided to cut out his vices after he first became a father in 2013 but admitted that it could have been disastrous as he suffered a vocal haemorrhage as a result of changing his habits.
Michael told The Times: "I stopped everything. No more booze and no more smoking and started going to the gym.
"Six or seven months later, I was in the studio singing and I could tell something was not right, I went to the doctor and it turned out I had a vocal haemorrhage."
Michael said doctors told him that his change of lifestyle could be responsible and they urged him to undergo an operation immediately.
Meanwhile, Michael recently confessed that he still gets nervous when his five-year-old son Noah, who is in remission from liver cancer after a devastating diagnosis two years ago, goes for check-ups.
He said: "We have to take him every three months for check-ups, and it's really scary ... One of the first things a doctor told me at one of the hospitals we'd gone to was to stay strong and help each other through this. When we had asked why the doctors keep telling us that, this friend of ours who works with families going through things like this, said that something like 92 per cent of couples who go through this ... get divorced. And many of the eight per cent who don't, have more children. And of course, my wife and I thought, here we are with a beautiful daughter."
And Michael - who also has Elias, three, and Vida, nine months, with his wife Luisana Lopilato - doesn't know if either himself or his wife would be "brave" enough to fight it again.
He added: "We were in the car yesterday and I actually looked at her, and said, 'Would you do it all over again?' She then answered, 'Of course I would do it all over again. I wouldn't want anything different. You guys are the greatest joy of my life.' But then my question to her was, 'But would you be brave enough to do it all over again?' And then she said, 'I don't know.' And I would have to say the same thing. I don't know."
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