I am trying to establish whether my teenage son needs to take fludrocortisone or not.  His PRA level is above normal (moderately elevated) His DNA and his presentation of CAH proves he is a salt loser. The odd thing is that PRA remains moderately elevated whether he takes it or not. He went from taking 2 mcgs a day to nothing. His blood pressure is better on the fludro but is not checked regularly, it drops slightly on standing but his pulse jumps sharply sometimes up to 40 beats on standing. Has anyone had this experience or any ideas?  Thanks in advance.