When we have human beings to focus our anger upon. Anger tends to escalate when we get in head to head confrontations with enemies. You say something, they say something back, you say something worse, on and on. Anger is a deadly sin when it tends to spin out of control for us. When it leads us to dehumanize our enemy then we are in real danger of hurting somebody, of even killing somebody.
Anger is serious business.
It must be handled with care, handled with prayer. Think about Jesus, and what he said about anger and what he did about anger. Jesus is teaching us to control the way we express our anger against those around us, whom we should always think of first as our brother or sister. To yell and scream at those we are angry with is the first step in the escalation of anger. Don't even let the angry back and forth start.