It's can be a dangerous business being an international singing megastar - just ask Lady Gaga.
The singer has had to postpone several US dates on her 'Born This Way Ball' world tour after a debilitating joint inflammation left her unable to walk.
Gaga called off shows in Chicago last Wednesday and Thursday and Detroit and Hamilton over the weekend after being diagnosed with Synovitis.
In a statement, the 'Bad Romance' singer said: "I am completely devastated and heartsick. I've been hiding this injury and pain from my staff for a month, praying it would heal, but after last night's performance, I could not walk.
She also tweeted her 34 million Twitter followers, saying: "I will hopefully heal as soon as possible and be at 500% again, which is what you deserve."
Gaga has been on the road with her 'Born This Way Ball' world tour for over two years, playing over 200 venues in six continents.