Borderline personality disorder (BPD) – sometimes also called emotionally unstable personality disorder.
Borderline personality disorder is a type of mental illness. Those who suffer from BPD struggle to regulate their mood and emotions, resulting in them being unstable - sometimes for long periods at a time. It can cause problems in relating to other people, and often makes controlling impulses difficult. There are two main types of BPD – impulsive and borderline. In the impulsive type, the main characteristics are a lack of control to impulses and emotional instability, sometimes with threatening behaviour in response to criticism.
The borderline type has some of the characteristics of emotional instability, plus difficulties with self-image, repeated emotional crises, low self-esteem and a sense of aimlessness in life.