Putin's health is just speculation at this point: we cannot know for sure (until he eventually keels over, that is).

The only thing we can see is that he is acting like a man in a hurry. There can be plenty of reasons for that, such as a disastrous demographic trend in the Russian population (aggravated by the Covid deaths), but this is long term. Many things could explain why Putin thought that this was now or never...

(and yes, levelheadedness might be the only thing that could keep us on this side of nuclear war)