Marie Osmond was rushed to the emergency room last night after performing in Las Vegas. Turns out the singer has "a bad lung problem," according to her rep, Alan Nierob.

Nierob tells TMZ that his client, who was diagnosed with a bad case of bronchitis, was released from the hospital's care after a few hours and is currently being seen by doctors. That's a smart move, since bronchitis can become nasty and/or hard to shake, and she isn't going to want this to get out of control.

Despite the diagnosis, tonight's show at the Flamingo in Vegas is still on schedule as planned. That doesn't meant it can't be canceled, but as of right now, it's still a go.

Osmond, 52, and her brother Donny are currently amidst a residency in Sin City, their first in 29 years. The siblings and former teen idols signed a two-year contract to perform at the hotel. Their last album, 'Donny and Marie,' made an impressive debut on the country charts earlier this year.