Céline Dion revealed Thursday morning that she's been diagnosed with stiff-person syndrome, a rare and incurable neurological disease that can cause debilitating muscle spasms.

In a tearful video posted to her Instagram account in both English and French, the Canadian singer said her condition would force her to postpone and cancel a series of upcoming concert dates.

"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," Dion, 54, wrote in the caption of the post. "It hurts me to tell you that I won't be ready to restart my 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 said in her 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."