A very common, negative consequence of anger is getting so angry you end up saying something you regret. It happens all the time. People become overwhelmed with anger and their desire for revenge overtakes everything else. Boom, they say something cruel or hurtful that can’t be taken back.
It’s a difficult thing to do but people need to find a way to stop, think through how they are feeling and how the other person is feeling, and then decide if and how they want to respond. Learning to do that can be the difference between letting your anger get the best of you and using your anger in a positive way.