Kelly Osbourne was rushed to hospital after suffering a seizure on the set of the LA produced television show "Fashion Police."
Witnesses said that just before the seizure, Osbourne turned to her co-host Melissa Rivers, who was filling in for Giuliana Rancic, and said: "I don't feel good", reported TMZ.
According to CBS Osbourne then fell from her chair and collapsed.
She reportedly began to shake and the seizure lasted for approximately 30 seconds.
Rivers, some crew members as well as a medico who was in the audience rushed to her side to provide first aid until the ambulance arrived.
Cameras captured her being placed into an ambulance on a stretcher. Her face and body was covered by a white sheet, and security personnel held up white sheets to shield her from cameras.
A representative for the star did not immediately respond to a request for comment, People Magazine reported.
The former reality star has openly struggled with her weight and substance abuse over the years.
In a magazine article this week, she told how she lost more than 69 pounds thanks to exercise, diet and some help from her vegan chef boyfriend.