What is codependency and what makes it unhealthy?

Codependency isn't simply an over-reliance on another person. It involves enmeshment, meaning your identity is intertwined with your partner's. In a codependent relationship, your focus is on the other person so much so that your needs, goals, and interests are suppressed and ignored.  You may be an independent person in that you're completely capable of earning a living, paying the bills, and taking care of the children (hard work, dependability, and caretaking are common traits among co-dependents). Still, you have an unhealthy need to be needed that keeps you dependent on someone else to make you feel worthy and lovable.

A need to be needed

Codependents build their self-worth on helping, fixing, and rescuing others. And as you can imagine, this creates an imbalance in their relationships. In order for codependent relationships to work, both parties must accept their roles – one as the caretaker or giver and one as the infirmed or taker.  As a result of childhood trauma, childhood emotional neglect, and dysfunctional family dynamics, a "giver" feels fundamentally flawed and unworthy and believes he must earn love. So, you sacrifice your own needs to feel accepted and valued. This creates an unhealthy dependency on others to validate your feelings, interests, beliefs, worth, and even your existence.  It's never healthy to depend on others to validate your worth. This need for external validation leaves many codependents trapped in abusive, unfulfilling, and unhappy relationships because they feel purposeless and unlovable without the caregiver role.