In a relationship, some experts say it's not about what you fight about or how much you fight. It's really about the way you fight. Do you call each other names you wouldn't call your mother? Do you bring up past mistakes that each of you made? Do you berate each other and say ugly things that you can't take back?
If so, you're fighting with someone you say you love in a divisive, hurtful way. And after a while, it's going to something that contributes to the demise of your relationship.