Celine Dion in tears as she demonstrates how a rare disease affects the voice

When Céline Dion revealed exactly how her rare disease affects her singing voice, she burst into tears.

“It’s very difficult for me to show you this,” said Dion, 56, as she breaks the fourth wall in her groundbreaking documentary. I am: Celine Dion.

Directed by Oscar nominee Irene Taylor, the feature-length film offers the singer’s fans a rare glimpse into her life after being diagnosed with the extremely rare stiff person syndrome (SPS).

Affecting only one to two people in a million, it is a progressive neurological autoimmune disease that causes muscle stiffness and painful spasms. It usually begins in the person’s trunk and then spreads to the arms and legs.

“Before SPS really hit me, my voice was the conductor of my life. I followed it,” she said in the film clip.

“‘You go first and I’ll follow.’ And that was fine with me because I had a great time. When your voice makes you happy, you’re at your best.”

Dion says of her voice: “‘You can be the leader, my ego is not that big. If you want to take over, I don’t care. I’m having a good time here.'”

After explaining how important her voice was to her, Dion then described the physical pain of the illness.

“Sometimes when I try to breathe, my lungs are fine. But what’s in front of my lungs is so rigid,” she said, trying to sing but having trouble hitting the notes or projecting her voice.

“There were moments when I had to go into the studio and I knew they wanted Celine Dion,” the singer said of the expectations placed on her as she tries to continue delivering her iconic voice.

She adds: “But who is Celine Dion? She has sung the highest notes of all time. She is the best.”

With tears in her eyes, the singer also reflected on her talent: “I think I was very good. I think I did some things that were incredible.”

Premiering on Prime Video on June 25, the documentary delves into Dion’s most notable achievements and her personal life to shine a spotlight on her fight back to the stage.

In one scene where Dion is confronted, she even suffers a “crisis” in which her foot becomes stiff and her whole body suddenly freezes. Her medical team was about to call 911 when the drugs they had given her took effect.

Dion explained that she rarely left her home in Las Vegas and wanted to make the documentary because she had always been an “open book” with her fans and no longer wanted to “lie to” them.

The Quebec singer is one of the most successful music artists of all time and has sold over 250 million albums worldwide.

Her number one hits include “The Power of Love,” “It’s All Coming Back to Me Now,” “My Heart Will Go On,” and “Because You Loved Me.”

She has won five Grammy Awards, two Academy Awards, seven American Music Awards and an incredible 43 Félix Awards – Quebec’s music awards

She received Diamond status as the highest-selling artist of all time at the 2004 World Music Awards and the Lifetime Achievement Icon Award at the 2016 Billboard Music Awards.

And as if that wasn’t enough, their Las Vegas performances remained the two highest-grossing of all time.

Two years ago, she revealed that her illness was causing muscle spasms that affected her ability to sing and walk.

“We are still researching this rare disease, but we now know it is the cause of all the cramps I have,” she said in a video on Instagram. “Unfortunately, the cramps affect every aspect of my daily life, sometimes I have difficulty walking and am unable to use my vocal cords to sing like I am used to.”

“I Am: Celine Dion” will be available on Prime Video on June 25th.