I have read that anger is a signal to us that something is wrong. So it's a healthy sign when we feel anger, but I think the question is what do we do with it. Not letting it be destructive to us or to other people is the question.
I think sitting with it, feeling it, letting time go by, waiting...then taking it back out, turning it around, examining it from all sides, when we are calmer...seeing if there is any "merit" here to consider and then act upon, once the steam quits coming out of our ears...
Most of us don't like feeling this way, so we blow off the steam very quickly OR we stuff it down and it turns into resentment and depression (anger turned inward).
I think we have to process our anger. My father is a rageaholic. I have watched him erupt in a New York minute and make himself and everybody around him miserable, over the tiniest little thing (usually somebody questioning his authority, i.e., disagreeing with him about anything). As he is getting older, now 83, he is getting worse. I think he is very angry that his body is betraying him...and instead of dealing with THAT, and facing that, he blows up at every little thing.
I feel sorry for him but I also don't like his behavior at all. He has no coping skills. By waiting, we are coping.