Popular Austallian-British actor and presenter Mariam Margolyes was rushed to hospital and is suffering a chest infection.
The star, who is perhaps best known for her role as Professor Pomona Sprout in the Harry Potter films, revealed the news to fans on Facebook.
The 81-year-old said that she "can't come home yet," in a post showing her in a hospital bed.
She went on to thank friends for their support, telling fans: "I did survive and am still in The Royal Brompton Hospital certainly till Sunday. I am growing energy but it’s still not quite me. I am putting this so you know how grateful I am for lovely messages."
The star explained that she will "slowly" be getting back to her roles and projects, including her book tour.
On Monday, Miriam Margolyes posted a "heartfelt" message to the hospital seeing her, saying: "Heartfelt thanks to all my wonderful friends who sent messages and to the very fine doctors and nurses at the RBHT who put up with me and put a TAVI in the LAVVY. HUGS. MM."
The Harry Potter star later updated fans adding: "I spoke too soon. Can’t come home yet: I have a chest infection. Probably tomorrow. But at least I’m resting. Love to all. Thank you for your lovely messages."
Miriam Margolyes reveals she's not a Harry Potter fan
Previously, Miriam revealed that he wasn't actually a Harry Potter fan, saying: “I’m not against it, I’m just not interested. I’ve never seen a film. I’ve never seen the books, I’ve never read them. I just pocket the money when it comes and I’m very grateful for it.
"I think that JK Rowling is a terrific writer, and I'm sure that Harry Potter's world is a good world. But it's not my world.
"I have to step very gingerly over the gap between you and me, and hope that you'll understand that despite the fact that I'm headmistress of Hufflepuff and you're in Gryffindor, I don't really want to talk about 'Harry Potter.'"
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