Here is a good site http://psychcentral.com/disorders/sx10.htm

Hi, Just so you will know, "BPD" is a very difficult disorder to both diagnose and also treat. It can manifest itself in many ways and some people who are "highly functional" people with BPD can seem very "normal" emotionally and then at home or if the wrong thing sets them off, they become an entirely different person. Similar to Dr Jeckel-Mr. Hyde. Generally, people with BPD have trouble with keeping relationships because they want love one minute and invite hate or anger from those around them at unpredictable times. This is of course very confusing to those around these individuals who are close to them but are at a loss as to why the person is acting the way they are. They often have other things which they do that are used often for diagnostic purposes: Eating disorders, obsessive compulsive disorders, anxiety/depression, suicidal thoughts, behavior and threats, self mutilation (cutting or burning themselves not to kill usually, but enough to scar themselves badly if done frequently) substance abuse issues, being very "clingy" to people and fearing abandonment, very unstable self image -- feel OK about themselves one day and hate themselves the next -- impulsive habits, in particular: spending money, sexual activity, binge eating and doing activities that are very reckless and dangerous. They often have very intense episodes of anger or rage, sometimes without any apparent cause at all. This disorder is so complex that many experts and therapists will refuse to treat someone who has BPD simply because there is no cure, and the patient is often very intelligent and difficult to treat, even if medicated and in talk therapy. So it is very frustrating for even the therapist. Some people get better as they grow older, for some reason, but it is a serious disorder. There is also a fairly high incidence of suicide over time, even if treated. So it is best to have the person treated and get help if they will, and also to watch them closely if possible, and of course take ALL suicide threats seriously. Hope this has been helpful for you.

i have boarderline personality disorder - BPD one of my psychiatrists described it as 'permanant teenager-ism' because our moods are as erratic as teens can be however, i think the fact that its called a personality disorder makes people assume that sufferes are beyond help and are therefore completely crazy. not true. there are treatments, not cure. havever as depression is commonly associated with BPD some shrinks perscribe antidepressants and refer you to a psychologist for cognitive therapy. in the end your rate of recovery depends on whether you commit to the treatment and accept help. love (: xoxox

inability to sustain friendships/relationships for a long time compulsive lying - they even believe their own lies nothing is ever good enough they are never satisfied they have difficulty in knowing right from wrong they dont have normal reactions and feelings they dont learn from their mistakes

BPD is, indeed, a difficult diagnosis to make. Check the DSM IV as a place to start. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)