A set of Lady Gaga’s shows have been postponed under strict doctor’s orders following an injury she sustained during a performance which has left her unable to walk.

The painful ordeal has been described as synovitis, a severe swelling of the joints. The singer took to Twitter to explain what was happening and to apologize to her fans for the show delays. Those affected include performances on February 13th and 14th in Chicago, February 16th in Detroit and Feb. 17th in Hamilton, Ontario, Canada.

There’s an unfortunate announcement coming out right now, concerning myself and the Born This Ball. Im so sorry. I barely know what to say.

— Lady Gaga (@ladygaga) February 12, 2013

I’ve been hiding a show injury and chronic pain for sometime now,over the past month it has worsened. I’ve been praying it would heal

— Lady Gaga (@ladygaga) February 12, 2013

I hid it from my staff, I didn’t want to disappoint my amazing fans. However after last nights performance I could not walk and still can’t

— Lady Gaga (@ladygaga) February 12, 2013

It will hopefully heal as soon as possible, I hate this. I hate this so much. I love you and Im sorry.

— Lady Gaga (@ladygaga) February 12, 2013

Due to a case of synovitis, (severe inflammation of joints) Gaga’s doctor has ordered her to postpone show in Chicago, Detroit + Hamilton

— Lady Gaga (@ladygaga) February 12, 2013