Managed anger is a positive, normal feeling like any other. When mismanaged though, problems can occur. In one moment, all the credibility you have built during a long period of time could be lost in a moment.
Understanding yourself and others can be a great help in the process of managing anger. Identify your triggers and find ways in which to communicate more effectively when angry. Triggers to anger can vary from differing values, unmet expectations to built up resentment or having too much to drink. Whatever the cause, if it affects someone else or yourself, take a step towards change.