Michael J. Fox has opened up about the crushing lows he experienced in the wake of his 1991 diagnosis with Parkinson's Disease.
He told the crowd at the 13th Governors Awards in Los Angeles that he spiralled into a seven-year long state of denial after doctors told him what his future may hold.
"[In 1991] I was on top of the world. I had a hit television show, two movies in the can and it was all good in the neighbourhood," the 61-year-old said during his acceptance speech.
"Somewhere in there around 29 I was diagnosed with Parkinson's. I was told I only had 10 years left to work."
He added: "That was s**tty. That's what happened. The hardest part of my diagnosis was grappling with the certainty of the diagnosis and the uncertainty of the situation."
The Back to the Future star revealed that the question mark now hanging over his life was tough to handle.
"I only knew that it would get worse. The diagnosis was definite," he said.
"The progress was indefinite and uncertain."
With uncertainty came denial, and Fox refused to tell the world and those close to him about his degenerative condition.
"I told very few people. And they kept my secret," he said.
"Then there were all kinds of doctors who helped me understand the physical processes that were at work, or not at work, in my brain, as the case may be.
"Finally, I felt like I needed to tell everybody. I understood it would have a huge impact on my career."
"What happened next was remarkable," the Family Ties star said.
"The outpouring of support from the public at large and the beautiful reaction from all of my peers in the entertainment business."
"It struck me that everything I had been given – success, my life with [my wife] Tracy, my family – had prepared me for this profound opportunity and responsibility. It was a gift."
He added: "All of you, thank you, and the people that I work with. It was transformative."
Fox went on to establish the Michael J. Fox Foundation in 2000 and quickly became the most famous advocate for finding a cure for the degenerative condition.
In 2020, the Back To The Future star announced he was retiring from acting due to the disease's progression.
Parkinson's disease is a lifelong condition that causes parts of the brain to deteriorate over many years, according to the NHS.
Symptoms can include stiff and inflexible muscles, involuntary tremors and slow movement.
To date, Michael J. Fox's non-profit organisation has funded about USD$1.5 billion (AUD$2.26 billion, £1.27 billion) of research.