It all happened on location during the filming of Die Laughing, in which he starred, co-wrote and was a producer. He was in his early 20s, a onetime teen idol now transitioning into bigger challenges with the promise of a long, successful career in Hollywood.
He didn't want to tell the truth: doctors had found a heart murmur when he was a teenager and for years he'd suffered similar symptoms.
"I remember passing out and was thinking, 'Wow, this is serious. But I better not tell anyone.' I was brought up very, very old school, and you don't tell anybody you're hurt or you're injured and you especially don't tell anyone that you have a heart problem," he tells PEOPLE. "It's career death. And the only thing I ever knew in my entire life were the arts. I had no perspective. I didn't understand life."
It's been more than three decades since that day. Benson went on to score more movie roles and became a sought-after television director (Ellen and Friends) and a professor at New York University. He voiced Beast in Disney's animated classic Beauty and the Beast and wrote songs, a novel, a musical and screenplays.
A New MemoirThe scar that runs down his chest is a reminder of the battles with denial, the excruciating pain, slow recoveries, frustrating setbacks and bouts of depression. It also speaks to what he's learned about medicine – and himself.
His new book, I'm Not Dead …. Yet!, offers a look at his long journey from Tiger Beat cover boy ("Win a pillow for your bed from Robby Benson," read one cover line in 1976), to health advocate. It's both a Hollywood memoir and an advice book for people facing major health problems, intimate and often humorous.
Today, Benson is 56 years old and lives in Cape Cod, Mass., with his wife Karla DeVito. They have two children. That boy-next-door look from Ode to Billy Joe in 1976 and Ice Castles in 1978 has given way to a beard and a mane of graying hair.
But despite decades of heart problems he remains in top physical form, still that fitness fanatic from the films Running Brave and Harry and Son who does hundreds of sit-ups a day and recently ran two 5K races.
Denial and DizzinessThe idea for the book, which in its electronic form is multimedia with songs, videos, photos and spoken word sections, came to him when he was recovering from his fourth open-heart surgery at the Cleveland Clinic two years ago.
"I was lying in bed. I was just coming out of anesthesia in the ICU and I went, I've got to write this book," he says. "I've been through this four times. And I've got to help other people navigate this brutal experience."
The toughest thing to learn was changing his attitude toward his health and body. He had stubbornly ignored the symptoms for years, then after surgery tried to rush his recovery, even running a 10K just weeks after he went home, only lengthening his healing process.
"My behavior was the perfect example of denial," he writes about the times he pushed on despite nagging breathing problems and dizziness. "Looking back, I was totally irresponsible for not getting myself to a doctor."
He's also had to confront cardiac depression, which is something doctors liken to a soldier's post-traumatic stress disorder. It often comes after a brush with death, the invasion of the body during surgery and recoveries that always take longer and hurt more than one anticipates.
"Cardiac depression is very powerful, it's very black, it's very dark," he says. "What I've learned to do is get out of my head and get into my heart. And it just sounds like an easy thing – it was difficult at first – to truly recognize moment to moment how fortunate I am."
Becoming a Health AdvocateAnd he's come to learn how to best navigate through the medical world, becoming skeptical and firm even while facing emotionally crippling life-and-death circumstances. And he's been misdiagnosed. One cardiac doctor, he says, lectured Benson on the dangers of drug abuse in Hollywood when in fact the problem was a bum heart valve.
"Doctors are human, they make mistakes, and you have to stay on top of them," he says. "You have to ask the second question, the third question, the follow-up to the fourth question."
It's difficult to do, he acknowledges, when you've just been told you may die. In his case, that first dose of news left him drifting in a strange out-of-body experience, with a show business twist. He saw himself starring in not just a movie about a guy with a heart problem, but a comedy.
"I went into some kind of a comic scenario in my mind," he says. "I remember looking at how many comic things I could find, how I would shoot them, how I could make people laugh. I said to myself: I hope Karla is listening. I may die. It was just very odd."
He and Karla DeVito, a singer/actress, had met while appearing in a New York production of The Pirates of Penzance and over the years DeVito has been that "most remarkable health advocate" that Benson says every patient needs.
"We have a relay situation, where my health will be in jeopardy and I hand the baton when it comes to making certain choices," he says. "We talk about everything that happens to us. And we learn as we go along."
And that, he says, is perhaps the biggest lesson of all.
"You need to have someone by your side who you love and trust, who loves you and trusts you, people you can talk these things through with because they're not secrets," he says. "This sounds bizarre, it sounds like I'm an old hippie, but you need to truly embrace it."
"If you fight it, you’re a fool," he continues. "If you're afraid of death, I would say, either fight for your life or come to grips with the fact you may not make it. And in doing that there shouldn't be bitterness. There should be a celebration. There should be an understanding of how lucky you are. That's how I feel."