Sharon Osbourne Says She Passed Out for 20 Minutes and Doctors Don't Know the Cause

Steven Ferdman/Getty Sharon Osbourne

Sharon Osbourne still doesn't know why she fainted on the set of Night of Terror, a ghost-themed TV show she is filming with son Jack Osbourne, on Dec. 16.

She was rushed to the hospital, but doctors still don't know why she passed out.

"I wish I could but I can't [tell you why]," Osbourne, 70, said on UK's The Talk Tuesday. "It was the weirdest thing — I was doing some filming and suddenly they tell me that I [passed out] for 20 minutes. I was in hospital. I went to one hospital, they took me to another hospital and I did every test over two days and nobody knows why."

On Dec. 19, Osbourne shared an Instagram photo and reassured her fans in the caption, "Back home and doing great! Thank you for all the ❤️ 🥰."

She received well wishes in the comments section, and Carrie Ann Inaba wrote, "Thank goodness! ❤️❤️❤️ 🙏🏼❤️🙏🏼,"

Amanda Kloots also expressed gratitude for Sharon's recovery, commenting, "Oh thank God ❤️."

On Dec. 18, Jack shared an update, telling fans that his mother was doing better.

"She has been given the all clear from her medical team and is now home," he wrote. "Thank you to everyone who has reached out with love and support."

Kevin Winter/Getty for Live Nation Sharon Osbourne with son Jack Osbourne

Jack did not reveal what happened, adding: "As to what happened to my mum — I'm gonna leave it to her to share about when she is ready."

Sharon's health scare comes after she tested positive for COVID-19 in May, around the time her daughter Kelly Osbourne and husband Ozzy Osbourne also contracted the coronavirus. She previously had COVID in December 2020, for which she was briefly hospitalized.

Sharon has recently been caring for Ozzy, 74, who suffers from Parkinson's disease and underwent a major operation in June.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.