Anger in healthy persons is diminished through action. It is an aversive, unpleasant emotion. It is intended to generate action in order to eradicate this uncomfortable sensation. It is coupled with physiological arousal. But it is not clear whether action diminishes anger or anger is used up in action.
Anger is induced by numerous factors.
It is almost a universal reaction. But so are threats to one's affiliates, nearest, dearest, nation, favorite football club, pet and so on. The territory of anger is enlarged to include not only the person but all his real and perceived environment, human and non-human. This does not sound like a very adaptive strategy. Threats are not the only situations to be met with anger.