Bill obviously has health/physical issues, but I think he’s also worried “sick” about Hillary’s server/email issue & probably even more so, the fact that the FBI recovered the emails she tried to have “wiped” and now is pursuing a 2nd investigation into corruption that includes the Clinton Foundation.
From last fall:
Hillary Clinton’s legal adviser warns her: Time to lawyer up
http://nypost.com/2015/10/03/hillary-clintons-legal-adviser-warns-her-time-to-lawyer-up/
“I think Bill takes the matter seriously. But Hillary is still acting as though it’s a political smear job by right-wing zealots.”
That server was set up for Bill after he left office. Hilary’s stuff was added to it. The FBI must have struck it rich. No wonder they have 150 agents on the investigation.