Justin Bieber has been postponing shows on his world tour.

Now we know why.

The 28-year-old jumped on IG this afternoon to update his fans on what's going on: paralysis on half of his face.

 

 

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A post shared by Justin Bieber (@justinbieber)

"As you can see from my face I have his syndrome called Ramsay Hunt Syndrome and it is from this virus attacks the nerve in my ear and my facial nerves and has caused my face to have paralysis.  As you can see this eye is not blinking and I can't smile from this side of my face.  My nostril will not move ... this is pretty serious, as you can see," Bieb's explained.

Bieber does expect a 100 percent recovery, but it could take a while.