During the filming of E!'s "Fashion Police," star Kelly Osbourne reportedly told guest host Melissa Rivers, who was filling in for Giuliana Rancic, "I don't feel good" before falling out of her chair. Ozzy's daughter then began shaking and an ambulance rushed to the scene.

The 28-year-old was suffering from a seizure and even though the Black Eyed Peas make fun of the condition in their song "Let's Get Retarded In Here," epilepsy and/or seizure is no laughing matter.

Osbourne was taken to the ambulance on a stretcher, covered by sheets to shield her from the media, TMZ reported.

"She's fine," Rivers said in a video posted Thursday afternoon on TMZ. "We just saw her."

After Osbourne's seizure scare, the star took to Twitter to thank concerned fans for their support and update them on her condition.

As of last night, it seemed doctors had not pinpointed the cause of the scary incident, as she said:

"Thank U [sic] all 4 [sic] UR [sic] beautiful well wishes yes I did have a seizure they are just trying to figure out why?"pic.twitter.com/pyZV4rDXsY.

The problem she now has is waiting to see what the doctors find or don't find. Having just one seizure will land a person in the hospital for days, up to a week, just for observation purposes.

If, during the observation period the person has another seizure, life, as the person is used to living is over.

This might be an inconvenience for many, but it is more of a burden on celebrities?

They are used to being on tight schedules, going from one city to the next, in many cases, one country to next without hesitation.

If doctors label Osbourne as an epileptic, she will not be able to fly (at least for a few months or up to a year), driving is also out of the question and taking daily medicine is a given.

Meaning, her career and livelihood will be placed on hold.

Spokeswomen for Sharon Osbourne, Kelly's mother, and Melissa Rivers, Joan's daughter and executive producer of "Fashion Police," declined to comment.