A clip from the Celine Dion documentary “I Am: Celine Dion,” released Thursday, shows the famous singer suffering a seizure and screaming in pain.

Dion publicly revealed that she'd been diagnosed with Stiff Person Syndrome in December 2023, but the depth of her painful battle had been kept secret until now. The video showed the singer in a vulnerable moment as she endured a seizure. The footage is painful to watch, as the star writhes in pain and moans helplessly while others try to comfort her and watch as she weathers the medical crisis.

Dion was in the middle of being filmed undergoing a medical examination regarding her condition when she suddenly became immobile and began to feel excruciating pain. The cameras continued to roll as doctors and medical personnel bound her arms and legs and stabilized her on the table.

Her anguished cries are a far cry from the melodic, harmonious voice that fans are accustomed to hearing.

Harrowing footage showed medical staff doing everything they could to help Dion as she continued to scream, her facial muscles tensed and her body showing signs of agony.

The medical team eventually administered a nasal spray to reduce the damage caused by the muscle spasms.

The cries of pain and medical attention continued for almost 10 minutes before the crisis was abated and Dion was able to sit up on his own.

The famous singer spoke about the fragility of her situation, TMZ.

LOS ANGELES, CA – NOVEMBER 22: Singer Celine Dion performs onstage during the 2015 American Music Awards held at the Microsoft Theater in Los Angeles, California on November 22, 2015. (Photo by Kevin Winter/Getty Images)

“Every time this happens I feel so embarrassed. I don't know how to describe it. I just feel like I have no control,” she said. (Related article: 'It could have been fatal': Celine Dion admits to dangerously high use of hard drugs)

The moving documentary, which was released on Amazon Prime on Thursday, offers the first glimpse into the star's health crisis.