appearances. Here is a nice summary of her problems and how they've been obvious to see:
http://www.dangerandplay.com/2016/08/06/hillary-clinton-stroke-seizure-coughing-fits/
That's why you had a coordinated dem/media/GOPe/globalist hit on him following the DNC.
It didn't work as planned because he is already bouncing back in the polls.