Madonna is usually a health fiend, but she had taken a turn for the worst after reportedly being diagnosed with anaemia, with doctor’s ordering her to rest instead of rehearsing for her upcoming tour.

The fitness fanatic has been under a lot of strain working out to a demanding schedule ahead of her Sticky & Sweet Tour, which kicks off next month, as well as battling divorce and affair rumours.

But The Sun claims the 49-year-old is now resting on doctor's orders, after medics found she was suffering anaemia, which causes a lack of oxygen in the organs.

The newspaper reports that the star is also suffering a knee injury and is recuperating in New York resort The Hamptons.

A source tells the publication: "Madonna is doing less than OK. She has been rehearsing for the tour and she is totally miserable. She's down physically and mentally.

"Madonna was told to go soft on work and rehearsals, so she will now take one proper day off every week and go easy in the mornings.

"She has a blood analysis done every few days - including one during last Friday's rehearsal in front of everyone."