Docs can you explain what is a borderline personality disorder?

Personality disorder: Any personality disorder is an established pattern of seeing oneself, of interacting with others, of mood changes, and of impulse control. This pattern needs to be dysfunctional or maladaptive in a person's culture in order to be a disorder.

Borderline: Personality disorders are enduring, inflexible patterns of inner experience & behavior causing significant distress in relationships, work, & other important areas. "borderline" applies to a person with unstable sense of identity; extreme fear of being alone; unstable relationships; impulsivity; affective instability; extreme anger; chronic suicidality or self-mutilation; mini-psychotic times.

Borderline: Intense fear of abandonment, being manipulative, impulsivity, a tendency to think of people and things in all good or all bad terms, self mutilating behaviors, drug and alcohol abuse, sexual impulsivity, a profoundly disturb sense of self, and extreme emotional volatility.