Sir Michael Gambon Memory Struggle: 'Harry Potter' Dumbledore Reveals Extent of Health Crisis

Sir Michael Gambon, perhaps most well-known for his role as Dumbledore in the "Harry Potter" series has revealed his severe issues with memory loss and his deteriorating health.

Gambon was scheduled to appear in "The Habit of Art" in 2009, but the stress of the work led to severe health issues and mental deterioration. The 72-year-old has been acting for over 40 years and took over the role of Dumbledore after Richard Harris died in 2002. He was preparing for "The Habit of Art" when he suffered a medical crisis and collapsed twice.

"I think it's linked to the memory," Gambon told The Times. "It was a really major, big part. I think I got so frightened that I collapsed. They did all sorts of tests of me and they couldn't find a thing. It's rather sad. I couldn't do it. That is linked with what is wrong with me – overwhelming fear."

Yet Gambon continues to work, though he has not taken on such big parts since the health scare. He did resign from "The Habit of Art" and described the experience as "rather sad."

"I have never admitted this before, so all these producers don't know. I'm lucky in as much as I get away with it," Gambon revealed.

He is next scheduled to appear in the one-man show, "Eh Joe," which does not require him to memorize any lines. Instead, he will just be able to go onstage and do what he loves best: perform. Gambon is also in the TV movie "Common," which is in post-production and will be released this year.

Gambon has a long history in film and theater. He made his film debut in "Othello," produced by Laurence Olivier in 1965. When he took on the role of Headmaster Albus Dumbledore, Gambon called the piece "no great feat."

"I never ease into a role – every part I play is just a variant of my own personality. I'm not really a character actor at all," Gambon told FutureMovies.