Actor Charles Lawson, best known as Jim McDonald on Coronation Street, has said he was diagnosed with exhaustion before suffering a mini-stroke on stage.
A doctor asked him whether he would consider pulling out of playing Ian Rankin's detective Rebus, he said.
But Lawson responded that he would "feel like a chicken" if he did.
He went on to have the stroke mid-show in Edinburgh this month. "I knew I hadn't a clue what was happening, and then it just all went black," he said.
Lawson is now back on tour in Rebus - Long Shadows with co-stars Cathy Tyson and John Stahl, and told BBC Breakfast he feels "very well".
The doctor who originally diagnosed his exhaustion asked how he would feel about pulling out. "And I couldn't because I was playing bloody Rebus," Lawson said.
He told viewers who may be in a similar position to "listen to your alarm bells".
He saw the doctor before the show opened in Birmingham in September.
"I didn't sleep properly for a month," Lawson said. "I lost a stone. [On] press night we opened and everything was fine and all reviews were good."
After two weeks in Birmingham, the show went on tour.
Lawson said: "First night in Edinburgh. Packed house. Second half, Cathy, John and myself were on stage. There's a 35-page scene, the climax of the piece, and I was looking at John and I was aware very quickly something was wrong.
"I went deaf. The colour changed - my vision changed."
He said he could hardly see Tyson, and thought Stahl was messing about by reciting lines from a different play.
"I remember feeling annoyed," he said. "And I remember moving to where I should have been, and there was a piece of me that knew something was wrong.
"And then big John just put his arm around me and said, 'Come on big lad, off you go'."
He told the audience on 8 October he thought he was going to faint, according to a review in The Edinburgh Evening News, and was replaced by an understudy for the rest of the show.
Lawson went backstage and said he felt fine within 20 minutes, but scans the following day revealed the transient ischemic attack (TIA) - or mini-stroke.
"I haven't had time to deal with it," he said. "I haven't had time to sit down and think because two days later I was back on stage."
The show is now at Manchester's Opera House and still has to tour in Northampton, Aberdeen and Guildford.
"I need to sit down and think about it," he added. "It is a great show and Ian loves it, which is the key to all of us. We've got four weeks to go, and then I'm going on holiday.
"Celebrities can whinge a lot but I'm not like that. I don't whinge, but I knew I was exhausted and I know I'm exhausted and when I finish this it's up to the Highlands for me. No signal, no phone, two dogs and my beautiful [wife] Debbie, who's looked after me."
How to spot a mini-stroke
A TIA is a temporary disruption in the blood supply to part of the brain, according to the NHS. The signs can be remembered with the word FAST:
- Face - the person's face, mouth or eye may have dropped to one side, and they may not be able to smile
- Arms - they may not be able to raise both arms and keep them there
- Speech - it may be slurred or garbled, or they may not be able to speak at all
- Time - dial 999 if you see any of these signs