GSB,
The days of the BA doc are long gone. If succesful you get an A4 medical decleration form to fill in which is very straightforward. Send in with a copy of your class 1 and its another tick in the box. I am sure if you have something strange with you that you declare then they may wish to see you.
Worry more about the Interview day and sim day before that point. If you do have something of concern then i am sure a call to recruitment or BA Health services would clear it up.
BigAir