Michael Buble has been taking "eight or nine" steroids before his gigs.
The ‘Haven’t Met You Yet’ crooner was battling a heavy cold during his UK tour and though he was often "hurting" on stage, he insists his fans make the pain worthwhile.
He said: "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."
The 39-year-old singer also revealed his generous side as he has given £1 from every ticket sold for his UK tour, totalling £125,000, to music therapy charity Nordoff Robbins.
He told The Sun newspaper: "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.
Michael Buble battles heavy cold
