Jennifer Lawrence "popped a rib" during filming for 'mother!'.
The 27-year-old actress - who plays Veronica in the Darren Aronofsky directed thriller movie - hurt her rib as well as "tore" her diaphragm whilst filming for the role.
Speaking to reporters at the Toronto International Film Festival, she said: "Emotionally I had to go to darker places than I would ever want to go in my life and I would never want to go there again. And finding a more sort of vulnerable, softer part of myself that I think I had been like covering up or shoving away for a long time ...
"I popped my chest rib and I tore my diaphragm. It actually took a long time to heal but emotionally I was better as soon as we finished that scene and we could just go home and drink wine."
Meanwhile, Jennifer previously revealed she told Darren he had "severe psychological problems" after she read the script for the movie.
She said: "It was an instant yes before I even read anything. He told me his ideas and I thought they were brilliant and unique and challenging. I've been a fan of his for years - I think he's bold and brave, and I think I said brilliant.
"But I've been a fan, so once he told me the ideas floating around in his head I said yes. Then I got a script and when I read it I threw it across the room and told him he had severe psychological problems. But it's a masterpiece."
And Jennifer confessed she felt "severely miscast" when she started shooting 'mother!'.
She explained: "That's what scared me and I thought I was severely miscast. I found time to find who she was while working with Darren and I was able to pull out this personality that I didn't know existed. Darren was lovely. Michelle Pfeiffer and Javier Bardem and everyone was great and super nice."