Mariah Carey has been struck with a respiratory infection.

The 47-year-old singer took to Twitter on Wednesday (15.11.17) to inform her fans that she is battling a ''lovely upper respiratory infection'' after having contracted the flu last week, and has been forced to cancel the first dates of her Christmas tour as a result.

Mariah wrote on the site: ''Lambs! Just in time for the holiday gift-giving season, it seems I've received a present of my own; a lovely upper respiratory infection after last week's flu. Bleak! You know there is nothing I love more than celebrating the holidays with my festive Christmas show, but I have to take my doctor's orders and rest until he says I can sing on stage. Until then, unfortunately, I have to cancel the first several shows of my upcoming Christmas tour. I'm going to do all that I can so that I can see you soon! (sic)''

The 'Touch My Body' hitmaker - who has six-year-old twins Moroccan and Monroe with ex-husband Nick Cannon - has cancelled her appearance at the Caesars Windsor in California, on November 17, as well as her November 18 show at The Chicago Theatre.

As of the time of writing, the future of her November 20 show at Sands Bethlehem Events Center in Pennsylvania remains to be confirmed.

Mariah's unfortunate health set back comes as she recently admitted she was surprised by how popular her 1994 Christmas hit 'All I Want For Christmas Is You' - which she wrote and produced with Walter Afanasieff - has been, and couldn't wait to play it for her fans during her Christmas tour.

Asked if she knew the hit would bring her so much success and revenue, she said: ''Oh my gosh, no no, never, no. I feel like this is something small compared to the rest of my catalogue. This song just continues to surprise me.''