Mariah Carey has checked herself into a hospital for "extreme exhaustion," her spokeswoman said Thursday.

Cindi Berger would not say what Carey's symptoms were or where she was.

Berger said Carey's busy schedule contributed to her illness and hospitalization Wednesday night.

"She's been working around the clock," Berger told The Associated Press.

In a separate statement, Berger said: "Carey has been hospitalized for extreme exhaustion after completing two movies, Glitter and Wise Girls, and simultaneously writing, recording and producing her album, the soundtrack Glitter."

The 31-year-old singer has canceled all her public appearances, including her performance at next week's MTV 20th anniversary in New York.

Carey came up with the story for Glitter, about an aspiring pop star. The film, in which she has her first starring role, is scheduled for release next month, along with the album — which will mark Carey's debut for Virgin Records after signing a multimillion-dollar contract.