The X Factor UK and America’s Got Talent judge was photographed returning to his London home Friday afternoon, smiling and flashing a thumbs up for the cameras.
“I’ve got a bit of concussion. I feel better now,” he said from his front door, thanking fans for their concern.
Cowell, 58, was rushed to the hospital early Friday morning after fainting and falling down the stairs. His rep said he couldn’t sleep and was trying to get a glass of hot milk.
A source told PEOPLE that the music mogul is concerned about feeling well enough to tape Saturday night’s live X Factor show on ITV and may have to pull out.
“I will be back, but I don’t know about tomorrow,” Cowell said.