Michael Buble has been taking "eight or nine" steroids before his gigs to battle a heavy cold.
The crooner was ill whilst out on his UK tour and though he was "hurting" often on stage, he insists the fans made it all worthwhile.
Speaking to The Sun newspaper he explained: "My trip's been great, the crowds have been nuts.
"Me and most of my crew and band came down with a pretty bad cold. I've been on eight or nine different steroids every morning, and also antibiotics.
"But it's worth it - on nights when we're hurting the audience carry us through it."
Revealing his generous side he also told of how he gave a £1 from each ticket sold - totalling £125,000 - to Nordoff Robbins, a music therapy charity.
"I came up with this a year ago after I played the O2 arena. My manager wanted to book the tour for 2014 and I said I'd only do it if we give back too.
"The UK has been so great to me and I thought it was time to put my money where my mouth was.
"I'm lucky I can help a lot of beautiful young people."
A spokesman for the charity said the cash will make a "huge difference" to the work it will do in 2015.
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