Lady GaGa has issued a public apology after cancelling shows due to suffering from chronic pain.

The 'Edge of Glory' hitmaker was forced to postpone several upcoming concerts after a severe injury over a month ago caused her severe discomfort and she claims she can barely walk due to the inflammation of her joints, known as synovitis.

Gaga wrote on her Facebook page on Tuesday (13.02.13): ''I barely know what to say. I've been hiding a show injury and chronic pain for some time now, [and] over the past month it has worsened. I've been praying it would heal.

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

Although the 26-year-old singer is in agony, she feels ''devastated'' to have cancelled two shows in Chicago, another in Detroit and a final one in Hamilton, Ontario.

Seeking her fans' forgiveness during with her apologetic message, she wrote: ''I hope you can forgive me, as it is nearly impossible for me to forgive myself. I'm devastated & sad. It will hopefully heal as soon as possible. I hate this. I hate this so much. I love you and I'm sorry.''

Gaga's 'Born This Way Ball' is expected to continue with a two-night stop in Philadelphia on February 19 and 20 and the cancelled dates are expected to be re-announced later on during the trip.