Phoebe Waller-Bridge says she was left shaking because of the exhaustion and pressure sparked by her success.
The writer and actress, 33, has enjoyed huge hits and numerous awards with Fleabag and Killing Eve.
She told the podcast How To Fail With Elizabeth Day: “During Killing Eve I had a physical reaction to the pressure I was under.
“I was shaking and I almost passed out in one of the offices one day and had to get picked up and go to a doctor.”
The star said she felt unable to take a break because the show was “the tank that’s moving forward…”
She added: “I felt like I just had to keep going. I got better at it with Fleabag but I was still so tired, I was still having shakes and stuff at the final take.”
Waller-Bridge previously made headlines during the podcast when she hit back at criticism over her privileged background.
“It’s not like my privilege created Fleabag,” she said. “I created Fleabag, but from a point of place in my life where I was able to sit and write.”