Gaga pulls out of Rock in Rio, posts photo of IV in her arm

NEW YORK (AP) - Lady Gaga has been hospitalized and forced to pull out of the upcoming Rock in Rio music festival in Brazil, citing "severe physical pain" and posting a photo of what resembles an IV in her arm.

The 31-year-old singer-songwriter wrote on Twitter that she had to take care of her body and asked fans for their "grace and understanding."

Her representatives said in a statement Thursday that Lady Gaga was suffering from "severe physical pain" that affected her ability to perform and that she was under the care of "expert medical professionals."

It wasn't clear what she was suffering from or where she was being treated. She posted a photo on Instagram of her arm with a needle in it and a tube running outside the photo's frame.

Rock in Rio, which starts Friday, is to feature Maroon 5, Fergie, Aerosmith, Bon Jovi, Red Hot Chili Peppers and Guns N' Roses.

Earlier this month, Lady Gaga postponed a Montreal concert, citing laryngitis and a respiratory infection. She has previously said she suffers from chronic pain from fibromyalgia.