Nicole Kidman reveals acting in The Undoing affected her personality

Nicole Kidman’s celebrated role in The Undoing caused worrying problems in her personal life, the Aussie actress has revealed.

Nicole Kidman is known for completely immersing herself in the characters she plays but her most recent project, The Undoing, really took a toll on her physical and mental health.

The Oscar-winner, 53, admitted that playing Grace Fraser, whose husband Jonathan (Hugh Grant) is on trial for murder in the HBO drama, created a “disquietness” to her personality.

“Suddenly, I was in this place. There was sort of a disquietness to my personality where I was uneasy, and there was duress on who I was,” Kidman explained on an episode of the WTF With Marc Maron podcast.

“I actually got really sick,” she revealed. ”I think this is a big thing that happens to actors. I went down for a week, because your immune system doesn’t know the difference between acting and truth when you’re doing those (roles).”

The Undoing, which streams on Binge, aired last year to critical and commercial acclaim.

RELATED: The Undoing most popular show on streaming service Binge

Nicole Kidman as Grace Fraser. Picture: BINGE/HBO

The Big Little Lies star added how she tried to keep her work separate from her family life but couldn’t develop “a technique to tell my brain and my body, ‘Oh, this is just acting.’”

“I haven’t learned to clean that out. It doesn’t really work for me,” she said.

“I go home and I don’t sleep well, and I’m not well. … It’s that disturbing for me.”

Kidman previously said her husband, Keith Urban, and daughters, Sunday, 12, and Faith, 9, helped “bring her back to reality” while playing Grace, who was ”very taxing”.

“You’ve got to have laughs when you’re doing stuff like this. Otherwise, it’s just too harrowing,” the Emmy winner told Sunrise. “I almost work from a deeper place now and thus it’s very taxing at times.”

Stream every episode of The Undoing on BINGE. New customers get a 14-day free trial and start streaming instantly. Sign up at binge.com.au

Nicole Kidman with her The Undoing mural that was painted in Kings Cross, Sydney, to celebrate the show on BINGE.

Luckily, Kidman said her family was able to live in New York with her while she worked.

“My family was with me, and just to have my little girls, and Keith, and have dinner with them brings immediate reality back. Suddenly the boundaries get set,” she added.

Kidman called being with family “that place where I can breathe and feel me”.

Nicole Kidman. Picture: Visual China Group via Getty Images/Visual China Group via Getty Images

“Keith provides an enormous amount of that and hopefully we provide that for him when he’s on tour because that’s the benefit of having a family that’s tight,” she gushed.

This article originally appeared on Fox News and was reproduced with permission