Madonna fears she will die on stage.
The pop superstar - who has played to sell-out audiences around the world for more than two decades - says her crippling anxiety attacks leave her so short of breath she has to compose herself before continuing with her performance.
She said: "I have moments where I feel incredibly invincible and know that I have the audience in my hand. I know that everything is absolutely perfect.
"And then I have panic attacks, where I feel like everyone is breathing my air, and I might just die on stage.
"I normally try to turn my back to the audience, take a deep breath and remind myself that it's all temporary."
The 'Material Girl' singer, who turns 50 in August, insists her problem is brought on by claustrophobia and has nothing to do with lack of confidence in her ability.
She added to Dazed and Confused magazine: "I'm not worried about f**king up - I really have a panic attack that everyone else is breathing my air. It's hard to describe. When you have panic attacks you cannot rationalise them.
"Obviously there's enough oxygen for me but it never happens outdoors, it's normally in indoor sports arenas that feel very close when suddenly I feel claustrophobic. It's not a fear of performing."