Cognitive Behaviour Therapist

It's important to realise several things about anger before you start tackling it. First, anger is a normal process that has allowed humans to evolve and adapt. It isn't a bad thing in itself, but problems occur if it isn't managed in the right way.
Anger is also a mixture of both emotional and physical changes. A big surge of energy goes through your body as chemicals, such as adrenaline, are released.
Once the cause of the anger is resolved, you may still have to deal with the physical effects - all that energy has to go somewhere.

Unhealthy Anger
This can be taken out on another person, such as a partner, or an object - by punching a wall, for example. This last option can lead down the road to self-harm.

The other alternative is to suppress the energy until the next time you're angry. This may mean you release so much pent-up emotion that you overreact to the situation. Realising this can lead to feelings of shame or frustration when you reflect on your actions.

Just letting your anger go in an uncontrolled fashion can quickly lead from verbal aggression to physical abuse - don't forget the other person is probably feeling angry with you too.

Healthy Anger
This is about fostering or nurturing the relationships and being able to view more than one option that could solve a problem or sit with the difficulty in any given situation. The ability to be healthily angry is due to being rational and seeing the bigger picture.