my cat is 4 year old neutered...

Question
my cat is 4 year old neutered male. he is pulling the long hair out of his back.  he appears healthy, seems to be a bit warm on his back by his tail.  

Answer
sounds like your cat may be stressed usually cats get stressed when something changes in there house it could be as big and a new baby or something that converts your atttention else where when it was usally for the cat or the change of litter could stress a cat out take him to the vet.