You have left a depressing influence behind you.

Your friend is disheartened and alarmed.

You have left him weaker, not stronger.
It may seem hard-hearted to appear to be unsympathetic with invalids, and those who are slightly or even seriously sick; not to take interest in their complaints; not to say commiserating things to them; but really it is the part of true friendship to help sick people fight the battle with their ills.

We ought, therefore, to guard against speaking any word which will discourage them, increase their fear, exaggerate their thought of their illness, or weaken them in their struggle.

On the other hand, we ought to say words which will cheer and strengthen them, and make them braver for the fight.