Many Justin Bieber fans were heartbroken when he abruptly postponed his Toronto shows this week, but now the pop star is explaining why the whole fiasco happened.

The shows were postponed just hours before they were supposed to take place, leading disappointed ticket holders to express their frustration.

Now, Bieber is offering an explanation for the postponed concerts, based on a serious medical reason.

View this post on Instagram

A post shared by Justin Bieber (@justinbieber)

He posted a video to social media explaining that he's suffering from Ramsay Hunt syndrome, which is caused by a virus affecting a nerve in the ear. 

Right now, it's paralyzing half of Bieber's face: in the video, he explains how he can't blink one of his eyes or smile with one half of his mouth.

"Obviously, as you can probably see from my face, I have this syndrome," Bieber says in the video.

"For those that are frustrated by my cancellations of the next shows, I'm just physically obviously not capable of doing them."

The video is flooded with comments from people hoping he'll get well soon and telling him to get lots of rest.

"It's gonna get better," says Bieber. "It will go back to normal, it's just time and we don't know how much time that's gonna be."

He also says in the video that he's doing facial exercises to try to help, and will mainly be taking this time to rest and get better.