Board Thread:Skyrim/@comment-139.216.236.57-20130605103831/@comment-6881629-20130720162953

You can, if you fight a Vampire theres a chance you can catch the disease Sanguinare Vampiris if you don't cure it (like a normal disease) you soon become a full Vampire. You can then only cure it then by going to Morthal and talking to Falion. Careful though without the DLC if you don't feed on blood for four days people will attack you on sight.