"I've been hiding a show injury and chronic pain for sometime now, over the past month it has worsened," she tweeted.
"I've been praying it would heal," she wrote. "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.
"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. It will hopefully heal as soon as possible, I hate this. I hate this so much. I love you and Im sorry."
Her website said she is suffering from synovitis or severe inflammation of joints.