Some of us were raised to unleash a flurry of angry words no matter the consequences, so long as you apologize later. Others were raised to bottle the anger up. Don't say anything if you can't say anything nice. All the while, never really knowing that one day the bottle would burst. It's not wrong to be angry. But it is wrong to mistreat others in our anger. 

When we’re continually letting ourselves get worked up about someone or something, it’s impacting our physical health. Our blood pressure is high, and the chemicals released with being angry can have lasting effects. There is an increased risk of heart disease, irritable bowel syndrome, fatigue, and some autoimmune disorders (Before forgiving - the effect of anger and resentment on the body, 2014).