Borderline personality disorder (BPD), also known as cluster-B personality disorder, is a neurological health disorder. BPD affects the way a person feels and thinks about oneself and others. Common signs and symptoms of the disorder may include fear of abandonment, self-injuries such as suicidal tendency, intense anger, irritability, dangerous behavior, mood swings, identity disturbance, and chronic feelings of emptiness. Currently, there is no single cause of this disorder. BPD can be caused by a combination of factors such as genes and brain compounds or neurotransmitters. Neurotransmitters are brain chemical messengers that transmit essential information throughout the brain and body.