SYDNEY, Australia (AP) - The lead singer of the hugely popular children's group The Wiggles announced Thursday he will stop performing after being diagnosed with a chronic condition that causes dizziness, fatigue and nausea.

In a video-recorded statement, Greg Page said a little-understood disorder called orthostatic intolerance had left him debilitated.

"It's not a life-threatening condition by any means, but it is one that's going to be with me for the rest of my life," said Page, 34, who is known for bright yellow T-shirt. "It means that I'll no longer be able to sing and dance as I want to, and as a result I've decided to stop performing with The Wiggles."

Page, who helped found The Wiggles in 1991, handed his yellow T-shirt over to his understudy, Sam Moran, who has been performing with the group for more than a decade as a backup singer and dancer.