Los Angeles (CNN) -- Lady Gaga suffers from a painful injury that has left her unable to walk, forcing the postponement of several shows, the singer said Tuesday.
"I've been hiding a show injury and chronic pain for sometime now, over the past month it has worsened," Lady Gaga tweeted Tuesday afternoon. "I've been praying it would heal."
The injury is a synovitis, a severe inflammation of joints, her Twitter postings said. She gave no details about how she suffered the injury.
Gaga tweeted that she hid the injury from her staff since "I didn't want to disappoint my amazing fans."
"However after last nights performance I could not walk and still can't," she tweeted.
Gaga's "Born This Way Ball Tour" was in Montreal, Canada, on Monday night.
"It will hopefully heal as soon as possible, I hate this. I hate this so much. I love you and Im sorry," she tweeted.
The next week of shows, set for Chicago, Detroit and Hamilton, Ontario, have been postponed under doctor's orders, she said.
"To the fans in Chicago Detroit & Hamilton I hope you can forgive me, as it is nearly impossible for me to forgive myself. Im devasted & sad," Gaga tweeted.
CNN's Jennifer Wolfe contributed to this report.