• The disorder typically involves an unusual degree of instability in mood and black-and-white thinking, or splitting. BPD often manifests itself in idealization and devaluation episodes and chaotic and unstable interpersonal relationships, issues with self-image, identity, andbehavior; as well as a disturbance in the individual’s sense of self.

• Individuals with BPD can be very sensitive to the way others treat them, reacting strongly to perceived criticism or hurtfulness. Their feelings about others often shift from positive to negative, generally after a disappointment or perceived threat of abandonment or of losing someone. Self-image can also change rapidly from extremely positive to extremely negative.

• Frantic efforts to avoid real or imagined abandonment. 
• A pattern of unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation.
• Identity disturbance: markedly and persistently unstable self-image or sense of self.
• Impulsivity in at least two areas that are potentially self-damaging (e.g., promiscuous sex, excessive spending, eating disorders, binge eating, substance abuse, reckless driving). 
• Recurrent suicidal behavior, gestures, threats or self-injuring behavior such as cutting, interfering with the healing of scars or picking at oneself (excoriation).
• Affective instability due to a marked reactivity of mood (e.g., intense episodic dysphoria, irritability or anxiety usually lasting a few hours and only rarely more than a few days).
• Chronic feelings of emptiness
• Inappropriate anger or difficulty controlling anger (e.g., frequent displays of temper, constant anger, recurrent physical fights).
• Transient, stress-related paranoid ideation, delusions or severe dissociative symptoms

(via borderlinebizarre)