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.