Borderline personality disorder is a mental illness marked by an ongoing pattern of varying moods, self-image, and behavior. These symptoms often result in impulsive actions and problems in relationships. People with borderline personality disorder may experience intense episodes of anger, depression, and anxiety that can last from a few hours to days.
Borderline personality disorder has historically been viewed as difficult to treat. But, with newer, evidence-based treatment, many people with the disorder experience fewer or less severe symptoms, and an improved quality of life.