Madonna is said to have developed a "serious bacterial infection" just days ago which reportedly led to a stay in an intensive care unit, with her tour now believed to be postponed.
The news - which comes just two weeks before the singer, 64, was due to embark on her Celebration tour - was shared by her manager Guy Oseary on Instagram earlier.
Sharing the news, he wrote in a statement this evening: "On Saturday, June 24, Madonna developed a serious bacterial infection which lead to a several-day stay in the ICU.
"Her health is improving, however she is still under medical care. A full recovery is expected. At this time we will need to pause all commitments, which includes the tour."
Guy concluded the statement by writing: "We will share more details with you as soon as we have them, including a new start date for the tour and for rescheduled shows."
According to PageSix, Madonna was found unresponsive and rushed to a hospital in New York on Saturday.
The outlet said it had heard that Madonna was intubated for at least one night before having the tube removed. It added that she's now said to be alert and recovering.
Her upcoming tour - which was announced earlier this year - had been due to launch in Canada on July 15 and was scheduled to run for six months until January next year.
It's not known which dates are now affected, or whether the entire tour is going to be delayed, though Madonna was due to visit various countries over the course of the tour.
Following its launch, the tour was due to head to venues in the US, the UK, Sweden and other countries in the coming months before concluding with concerts in Mexico next year.
The tour is expected to celebrate her decades-long career in the music industry, which has included numerous chart-topping singles such as Like a Prayer, Vogue and Into the Groove.
Over the course of her career, the singer has received much acclaim, including having won several Grammy Awards and considered a leading figure in pop music.
It was previously teased that the tour will take fans "on Madonna's artistic journey through four decades and pays respect to the city of New York where her career in music began."
Madonna said in a statement when the tour was first announced: "I am excited to explore as many songs as possible in hopes to give my fans the show they have been waiting for".
Rehearsals had been underway for a few months now, with Madonna having previously shared glimpses of her practising for herself return to the stage on social media.
