Contrary to popular opinion (even among professionals), anger isn’t necessarily bad or destructive to a relationship. All couples have conflicts and frustrations. It is not the anger itself that separates successful couples from other couples. Rather, what separates them is how anger is handled and how the partners communicate with each other while angry over the issues that bother them.
For instance, communicating with sarcasm or contempt are very destructive modes of communication that will bring down a relationship if done too often or too intensely. Another very destructive pattern of anger is something called passive-aggressive where the hostility is kept undercover, but the partner “gets even” with the other with snide remarks, emotional withdrawal, or underhanded actions which sabotage the other.
On the other hand, research shows that communicating anger in a straightforward way can be healthy for a relationship, as long as it is done correctly. For instance, successful couples use what is known as a “soft startup” which does not antagonize the other causing them to stop listening to you.
Furthermore, successful couples have the ability to complain but not criticize the other over an issue that is bothering them. Registering a complaint can be  healthy for a marriage, but attacking the character of your partner(criticizing)  over the issue is not.
As we teach in our anger management classes and in our online anger programs, successful relationships depend on partners having learnable skills to make the relationship successful. Among these is the skill of expressing and communicating anger in ways that resolve the conflict, that don’t drive an emotional wedge between the partners, and that allow both partners to feel better about things later.