Anger is often considered a negative emotion, but it is just an emotional message that makes you aware of and react to your surroundings. It is both positive- when you can let it out in a natural way, giving you an awareness and negative- when it becomes unmanageable, leading to affect us both physically and mentally. It often can lead us to repress our emotions or become aggressive, which are both unhealthy effects of anger. You can manage your anger with techniques that better fit you, like being mindful and having an optimistic outlook. 

https://yourmentalhealthpal.com/effects-of-anger/