Anger is normal emotional state that can vary intensity. Anger can lead to both physical and biological changes.When you become angry, your heart rate and blood pressure increases. Additionally, your adrenaline and noradrenaline hormones also increase. These physical and emotional changes can be a result of events occurring in the environment, or a result of memories that are triggered in your brain which in lead to the emotional reaction.The response is a reaction to the memory.However, the response may not be a healthy response.

Source: www.apa.org

https://www.apa.org/monitor/mar03/advances