Celine Dion is giving fans a raw look at her life with stiff person syndrome.

In a newly released documentary, the iconic singer suffers a frightening medical crisis during a physical therapy session, and it was all caught on camera.

In 2022, Dion revealed she had been diagnosed with stiff person syndrome, but in her new documentary, I Am: Celine Dion, the singer shares she had been dealing with symptoms of the rare, progressive neurological disorder for 17 years.

“I need my instrument. And my instrument was not working. So we started to elevate the medicine,” Dion, 56, said after experiencing difficulty hitting certain notes during her 2018 and 2019 tours.

Although she completed her 2018 tour, Dion was forced to postpone several dates from her 2019 tour due to the “common cold” before the pandemic shut it down.

Her tour resumed in 2022, but once again she had to continue canceling and rescheduling shows. It wasn’t until she announced her diagnosis that she officially canceled the rest of her appearances.

“I can’t lie anymore,” Dion says in the doc. “From a sinus infection to an ear infection to whatever. Sometimes I would point my microphone toward the audience, and I would make them sing it. There’s moments where I cheated and I tapped on the microphone like it was the microphone’s fault.”

Also in the documentary, Dion shares an extremely vulnerable moment where she experiences a full-body spasm.

While laying on a massage table and going through some exercises with her physical therapy, Dion’s foot begins to cramp. Within minutes her entire body seizes and locks up to the point where she is unable to communicate with those in the room with her.

As the camera continues to roll, another member of her medical team comes into the room with benzodiazepine nasal spray and administers it to Dion, who, though motionless, is crying out in pain. The video is painful to watch.

Once the spasms have subsided – they typically last anywhere from 30 minutes to an hour – Dion is able to sit up and speak.

“Every time something like this happens, it makes me feel so embarrassed,” she says. “I don’t know how to express it, you know, to not have control over yourself.”

Her physical therapist speculates the attack was brought on by being “overstimulated” from an earlier singing session.

“If I can’t get stimulated by what I love, then I’m going to go on stage, and you’re going to put the pulse oximeter on me and turn me on my back?” she wonders.

Dion hopes that one day soon she’ll be able to return to the stage. You can watch the harrowing footage of her seizure here.