Lady Gaga has been hospitalised with "severe pain".
The Poker Face singer - who recently revealed she suffers from fibromyalgia, a disorder characterised by muscular pain accompanied by fatigue, sleep, memory and mood issues - has apologised to fans in Brazil after having to pull out of her appearance at Rock In Rio on Friday.
She wrote on Twitter: "Brazil, I'm devastated that I'm not well enough 2 come to Rock In Rio. I would do anything 4 u but I have to take care of my body right now.
"I ask for your grace and understanding, and promise that I will come back and perform for you soon.
"I was taken to the hospital its not simply hip pain or wear & tear from tour, I'm in severe pain. I'm in good hands w/ the very best doctors (sic)"