There is no evidence? or there is no discloser? You, nor I, have any idea if the felon Hillary is hiding medical issues, and blaming the media for pointing out the obvious signs/symptoms she has been showing on the public stage is more you being disingenuous than them. It is up to the felon Hillary to prove that she is not hiding illness, not for the public or media to give her the benefit of the doubt, she does not deserve that, the felon Hillary is a trained pathological liar after all, and cannot be trusted at her word.
There are two issues here: One is what obligation Hillary has to transparency, and the other is the ethical obligation of organizations purporting to report the news and offer editorial commentary.
As to the former, Hillary's main impulse has long been toward secrecy and privacy. It's not a desirable trait for a candidate for so public an office. At the same time though, it's a bit understandable to me given how her political opponents can turn anything at all into a vast conspiracy. She's been trained by long experience to hide anything you don't need to reveal. But, that being said, there is essentially no health problem that she could possibly have that would lead me to consider not voting for her at this point. She could be suffering from advanced dementia
and schizophrenia, and I'd probably still vote for her because the GOP nominee is so thoroughly unacceptable on so many points. That may be a bit of an exaggeration, but only a little bit. So it's true that I give her a pass on this that I wouldn't if she had an opponent who I could consider voting for.
None of that, however, justifies the Right-wing effort by supposed news organizations to invent a story from whole cloth. You want to see her medical records? Fine, ask for those. Note the difference in transparency between Trump and Clinton. This is what mainstream outlets have done with the issue of Trump's tax returns. If there is actual evidence apart from the records of a real problem, report on that. But it's ethically dubious at minimum, lacking evidence of an actual problem, to try to invent one.