Lady Gaga is suffering from a painful joint injury that has left her unable to walk in recent days, forcing the postponement of several shows, the singer said.
"I've been hiding a show injury and chronic pain for sometime now, over the past month it has worsened," Tweeted Gaga. "I've been praying it would heal."
The injury is a synovitis, a severe inflammation of joints, she added.
The 26-year-old gave no details about how she suffered the injury.
Lady Gaga hid the ailment because "I didn't want to disappoint my amazing fans ... however after last nights performance I could not walk and still can't."
Her "Born This Way Ball Tour" was in Montreal, Canada, Monday.
"It will hopefully heal as soon as possible, I hate this. I hate this so much. I love you and I'm sorry," she tweeted, adding that she basically has no choice.
Her next week of shows, set for Chicago, Detroit and Hamilton, Ontario, have been postponed under doctor's orders. Hopefully after that she'll be back.
"To the fans in Chicago Detroit & Hamilton I hope you can forgive me, as it is nearly impossible for me to forgive myself. I'm devasted & sad," Gaga tweeted.
Get well soon, LG.