Katy Perry has admitted that she suffers from obsessive-compulsive disorder (OCD), a condition that can cause people to become upset when their routine is disturbed.

"I certainly have an OCD side when I'm on tour... What are my areas of OCD? Well, if there's broken make-up in my purse I freak out. Also if I am around household pets and some of their fur comes off on my cardigan, then I can get pretty sharp," the Daily Express quoted her as telling Q magazine.
"But my worst one is if I see a pair of sunglasses with fingerprints on them. Truly, I cannot stand it. I go ape. 'Oh my God, I can't breathe! Wipe them clean! Agghhh,'" she added.
Source-ANI