You're in for a fun ride, wikipedia even has an article on just this: Health and Appearance of Michael Jackson.

In short: some kind of body dysmorphia, vitiligo, way too much money, and probably a personality disorder. He had so much plastic surgery done to his nose that the plastic actually broke through the surface of his nose. There is a lot of back and forth as to whether or not he was a child sexual predator or just trying to recapture a stolen childhood as an abused child star.