From Slash:
Show is postponed in Reno tonight. Bummer! En route to LA. Iii|; )'about 4 hours ago via Facebook
Illness sidetracks Ozzy's 'Crazy Train'(CNN) -- Heavy metal madman and reality TV star Ozzy Osbourne canceled a show in Reno, Nevada, Sunday night due to a "sudden illness," the concert promoter said.
"Based on advice from doctors, it is with great regret that Ozzy Osbourne is postponing his show ... at the Reno Event Center," Chris Martinez with Live Nation said in a statement. "The multi-platinum Rock & Roll Hall of Famer cannot perform ... due to a sudden illness."
The statement did not elaborate on what ailed Osbourne.
http://www.cnn.com/2011/SHOWBIZ/Music/01/31/ent.ozzy.illness/