president's visit to the hospital for this irritation in his throat. what was that all about? >> the white house says that this is a sore throat they say is cassed by acid reflux. they tell us this is something president obama had been complaining about the last few weeks. he saw the white house doctor. they noticed inflammation and then did extra tests where he had a ct scan done. the white house tells us it's done out of an abundance of caution. they say the results of the scan were normal and that no biyopsy. his history as a past smoker could play into here. here's what cnn's sanjay gupta has to say. >> if he is still smoking -- we don't know, but if he is, that could be contributing to his