Celine Dion said she has suffered from terrifying symptoms for years and decided to reveal her rare disease once the burden of lying to fans about her condition became "too much."

The Canadian star spoke about her life-altering neurological disorder in a preview of her interview with Hoda Kotb on NBC, which airs tonight, saying she had to stop performing early on to understand what was wrong.

The 56-year-old singer says she first began to notice symptoms of Stiff-Person Syndrome during her "Take Chances" world tour in 2008, where her voice faltered during performances in Germany and her body became more stiff.

Dion says she and her team remained silent about it because they did not know what was happening to her health.

It took more than a decade of tests and treatments before Dion received an official diagnosis of Stiff-Person Syndrome, a progressive condition that leads to muscle stiffness and painful spasms.

Dion says she finally shared her diagnosis with the world in December 2022 because she felt she was "lying" to the people who got her to where she is today.

She told Kotb that her body was betraying her while her husband René Angélil was dying from cancer, and she was trying to raise their children.

Dion said her condition became so severe that at one point she suffered from "broken ribs" due to the spasms.

"I should have, stopped, and taken the time to figure that out."

But the singer is committed to returning to the stage, even if she has to "crawl."

She said, "I am Celine Dion, because my voice today will be heard for the first time, not just because I have to, or because I need to, it's because I want to and I miss it."

The full interview with Dion airs on NBC at 10 p.m. ET.

A documentary about her health struggles, "I Am: Celine Dion," is set to premiere on June 25 on Prime Video.