Mary-Kate Olsen has been hospitalized with a kidney infection, her rep tells PEOPLE.
The actress entered the emergency room of a New York hospital on Monday.
"Mary Kate got a kidney infection," says rep Nicole Caruso. "She's resting comfortably and will be released in the next day or so."
The actress, who turned 21 in June, recently said she was in good health.
"Mentally, physically, I feel pretty on top of my game right now," she told EW.com in September, as she prepared for her debut in Showtime's Weeds. "Talk to me next week, I don't know. Today, I feel good."

Comments (1)
What my mother told my wife... (Below threshold)1. Posted by JoeC | November 20, 2007 8:51 PM | Score: 0 (0 votes cast)
What my mother told my wife about newlywed's complaint: Drink lots of water and pee after sex. (after my wife suffered her third kidney/bladder infection... it was a coooolddddd winter in Chicago!)
1. Posted by JoeC | November 20, 2007 8:51 PM |
Score: 0 (0 votes cast)
Posted on November 20, 2007 20:51