Sharon Osbourne still hasn’t got to the bottom of what happened when she fainted while filming last month.

The star returned to screens on Tuesday night, appearing on “TalkTV”, when her co-host JJ Anisiobi asked her to explain what had triggered her medical emergency and say what happened.

Osbourne responded, “I wish I could but I can’t. It was the weirdest thing — I was doing some filming and suddenly they tell me that I felt…” as Anisiobi asked, “Passed out?”

Osbourne continued, “Yeah, 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.”

READ MORE: Sharon Osbourne Shares Update After Being Hospitalized Following Health Scare

Anisiobi then said, “So they still don’t know why you passed out?” as Osbourne insisted, “No.”

Osbourne was rushed to hospital in Ventura County, California on Dec. 16 after falling ill while filming the “Night of Terror” TV show with her son Jack.

READ MORE: Kelly Osbourne Secretly Welcomes First Child With Sid Wilson — Sharon Osbourne Reveals Baby Boy’s Name

The following week, the TV personality assured fans she was doing OK, posting a photo of her husky Elvis posing in front of a Christmas tree.

She captioned the shot: “Back home and doing great! Thank you for all the ❤️ 🥰”

Details about Osbourne’s condition and the nature of the emergency remained vague at the time, but her son Jack took to his Instagram Story to set a few things straight.

“Ok here is what I’ll say — first things first MY MOTHER WASNT FILMING A EPISODE of @ghostadventures. She was filming a new episode of ‘Night of Terror’ with me. Hahaha,” he wrote last month.

He continued, “Now that we have made that clear… She has been given the all clear from her medical team and is now home. Thank you to everyone who has reached out with love and support. As to what happened to my mum — I’m gonna leave it to her to share about when she is ready.”