The key features of borderline personality disorder include impulsive actions, rapidly shifting moods, and chaotic relationships. A person with borderline personality disorder often shows signs of dependency and separation anxiety. People with borderline personality disorder often have an unstable self-image and threats of self-harm, such as suicide or self-mutilation (e.g., cutting or burning) are not uncommon. (Phillip W. Long, 2009)

Genetic studies have shown that genetic factors may play a part in the risk for developing borderline personality disorder, especially among direct generations. Certain physical characteristics of the brain have been found to be common among people diagnosed with borderline personality disorder. A study done by Tebartz van Elst in 2003 found those test subjects diagnosed with borderline personality to have a hippocampi 20 percent smaller than those from a mentally healthy control group. (Phillip W. Long, 2009) In this same study, the amygdalas were also found to be smaller, by 24 percent. Other common physical characteristics include damage to the frontal cortex. It has also been noted that the chemical dopamine may play a part in the presentation of the disorder.

Treatment of the disorder includes both psychological and pharmacological methods. In-patient therapy can be useful because of the tendency toward self-harm and impulsivity. Two methods of therapy found to be effective for this disorder include cognitive therapy and emotional awareness training. Pharmacology has not yet provided a consistent treatment for borderline personality disorder. But there are some medications that reduce certain symptoms. Commonly prescribed medications include antidepressants, antipsychotics, anti-anxiety and mood stabilizers. (Phillip W. Long, 2009)