Are there any side effects i.e. any hormonal changes , dopamine release when we get anger or while we shout or outburst in anger?
Because we feel satisfied getting anger in a situation than keeping our emotions shut!
This is actually a pretty complicated question.
In general, there isn't a lot of consistent evidence that would suggest that discrete emotions like anger have stereotyped response patterns. Anger is a fairly heterogeneous emotion category, meaning that it may not look the same (and have the same outcomes) in any given situation. Consequently, there may not be a good (or at least simple) answer to your question. This is the "psychological constructionist" argument (for a comprehensive overview, see Barrett & Russell, 2014).
On the other hand "basic emotion" proponents (Ekman, Izard, Panksepp) would suggest that activation of an "anger circuit" in the brain reliably produces a particular response pattern (e.g., feelings of unpleasantness, high arousal, approach motivation, certain facial expressions, hormonal changes, etc.). However, attempts to match these responses with specific emotions like anger have never quite worked out. Also, recent meta-analyses looking at emotion in the brain don't seem to support this perspective (e.g., Lindquist et al., 2012).
Edit: I don't find Wikipedia's explanation (linked by Mike) to be particularly convincing since it cites an article published 15 years ago. Emotion research has come a long way since then.
For basic emotion arguments, see: Ekman & Cordaro 2011
You can glance at Wikipedia to get a first impression:
According to Novaco, "Autonomic arousal is primarily engaged through adrenomedullary and adrenocortical hormonal activity. The secretion by the adrenal medulla of the catecholamines, epinephrine, and norepinephrine, and by the adrenal cortex of glucocorticoids provides a sympathetic system effect that mobilizes the body for immediate action (e.g. the release of glucose, stored in the liver and muscles as glycogen). In anger, the catecholamine activation is more strongly norepinephrine than epinephrine (the reverse being the case for fear). The adrenocortical effects, which have longer duration than the adrenomedullary ones, are mediated by secretions of the pituitary gland, which also influences testosterone levels. The pituitary-adrenocortical and pituitary-gonadal systems are thought to affect readiness or potentiation for anger responding.
Neuroscience has shown that emotions are generated by multiple structures in the brain. The rapid, minimal, and evaluative processing of the emotional significance of the sensory data is done when the data passes through the amygdala in its travel from the sensory organs along certain neural pathways towards the limbic forebrain. Emotion caused by discrimination of stimulus features, thoughts, or memories however occurs when its information is relayed from the thalamus to the neocortex.
Anyhow I can't access the reference papers but this should be a good starting point..