Power imbalance: A relationship between two people should offer an equal distribution of power, an imbalance can lead to a controlling or abusive relationship as one party (stereotypically the male) has the ability to influence through verbal, physical, sexual or other means to alter the behaviors and attitudes of the other.
Lack of communication: A healthy relationship should involve an active initiative by both parties to communicate clearly, honestly and without alterior motive about the emotions, experiences and possible issues of the relationship as per their experience. Not communicating enough, honestly or superficially can cause an emotional discord, arguments and the breakdown of said relationship. Communication is a key stepping stone in creating healthy relationships and stopping the formation of abusive or generally unhealthy relationships.
