When we went to see Hannah here in California, she said at the very beginning of the concert that she wasn't feeling good and for everyone to help her out by singing along to all the songs - You really couldn't tell she wasn't feeling well though - (This was back in November)
But have you looked at her touring schedule??? It is grueling! She will do like 3 concert nights in a row, then one day off, then 3 more, etc - When I looked at it, I thinking to myself, poor thing - there's no time to rest!
I hope she doesn't push herself so much next tour (or her manager, etc)