Originally published December 8, 2022 on Prevention.com

Celine Dion surprised fans on Thursday when she revealed insight about her health: She has a rare condition called stiff person syndrome.

“I’ve been dealing with problems with my health for a long time, and it’s been really difficult for me to face these challenges and to talk about everything that I’ve been going through,” the 54-year-old singer said on Instagram, before noting that she won’t be able to restart her tour in Europe in February.

“Recently, I’ve been diagnosed with a very rare neurological condition called stiff person syndrome, which affects something like one in a million people,” she shared in the post’s video. “While we’re still learning about this rare condition, we now know that this is what has been causing all of the spasms that I’ve been having.”

The comments of her post were flooded with well-wishes, but the message naturally raises questions about stiff person syndrome and what it means for someone’s health. Here’s what you need to know.