What are the side effects of Anger? 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 &amp; 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.

Edit2: Sources


For general psychological constructionist arguments about the nature of emotion, see: Barrett 2006 and Barrett 2014
For basic emotion arguments, see: Ekman &amp; Cordaro 2011
For reviews on mapping physiological changes to emotions, see: Cacioppo et al. 2000, Stemmler 2004, and for a theory-driven review of reviews/meta-analyses see Quigley &amp; Barrett 2014