The expression of emotion by another person, especially feelings of sadness, can put us ill at ease. It's difficult to find the “proper” distance, to show concern without appearing to be intrusive or indiscreet. Sometimes indeed, we can be quite clumsy!
Above all, show that you're there, simply that you're there!
In the busy daily flow, even the simple act of marking a pause to take the pulse of the situation, is not always easy to do.
For we are ourselves disoriented by the unexpected attitude, and need to take a step back to adjust.
Resist the urge to console
A common reflex, when faced with another person's sadness: seeking to reassure, to console a hurt of which we generally know nothing, to “think positively”.
It is better to accept that pain be expressed, even to remain silent.
When the person before us seems really to be upset, we sometimes hesitate to inquire because we're afraid to appear intrusive, to reopen the wound, etc.
So a “no-risk” question that's almost always on the mark for expressing one's presence and one's availability: “Can I help you?” or “How can I help you?”
Even if the person does not know what to respond, they can, if they want, take this question as an invitation to express themselves.
This question is particularly suitable for situations where you do not know the reason for the person's distress.