In his column in the April edition of Tabletalk, John Piper writes this: "In marriage, anger rivals lust as a killer. My guess is that anger is a worse enemy than lust. It also destroys other kinds of camaraderie. Some people have more anger than they think, because it has disguises. When willpower hinders rage, anger smolders beneath the surface, and the teeth of the soul grind with frustration. It can come out in tears that look more like hurt. But the heart has learned that this may be the only way to hurt back."
He goes on to say that "one of the greatest battles of life is the battle to 'put away anger,' not just control its expressions." To that end, he offers a series of 9 biblical weapons that will help fight the battle.
You can read about those weapons in Killing Anger.