Here is a quote from this site http://www.palace.net/~llama/psych/bpd.html
The DSM-IV gives these nine criteria; a diagnosis requires that the subject present with at least five of these. In I Hate You -- Don't Leave Me! Jerold Kriesman and Hal Straus refer to BPD as "emotional hemophilia; [a borderline] lacks the clotting mechanism needed to moderate his spurts of feeling. Stimulate a passion, and the borderline emotionally bleeds to death."
Traits involving emotions:
Quite frequently people with BPD have a very hard time controlling their emotions. They may feel ruled by them. One researcher (Marsha Linehan) said, "People with BPD are like people with third degree burns over 90% of their bodies. Lacking emotional skin, they feel agony at the slightest touch or movement."
1. Shifts in mood lasting only a few hours.
2. Anger that is inappropriate, intense or uncontrollable.
Traits involving behavior:
3. Self-destructive acts, such as self-mutilation or suicidal threats and gestures that happen more than once
4. Two potentially self-damaging impulsive behaviors. These could include alcohol and other drug abuse, compulsive spending, gambling, eating disorders, shoplifting, reckless driving, compulsive sexual behavior.
Traits involving identity
5. Marked, persistent identity disturbance shown by uncertainty in at least two areas. These areas can include self-image, sexual orientation, career choice or other long-term goals, friendships, values. People with BPD may not feel like they know who they are, or what they think, or what their opinions are, or what religion they should be. Instead, they may try to be what they think other people want them to be. Someone with BPD said, "I have a hard time figuring out my personality. I tend to be whomever I'm with."
6. Chronic feelings of emptiness or boredom. Someone with BPD said, "I remember describing the feeling of having a deep hole in my stomach. An emptiness that I didn't know how to fill. My therapist told me that was from almost a "lack of a life". The more things you get into your life, the more relationships you get involved in, all of that fills that hole. As a borderline, I had no life. There were times when I couldn't stay in the same room with other people. It almost felt like what I think a panic attack would feel like."
Traits involving relationships
7. Unstable, chaotic intense relationships characterized by splitting (see below).
8. Frantic efforts to avoid real or imagined abandonment
Splitting: the self and others are viewed as "all good" or "all bad." Someone with BPD said, "One day I would think my doctor was the best and I loved her, but if she challenged me in any way I hated her. There was no middle ground as in like. In my world, people were either the best or the worst. I couldn't understand the concept of middle ground."
Alternating clinging and distancing behaviors (I Hate You, Don't Leave Me). Sometimes you want to be close to someone. But when you get close it feels TOO close and you feel like you have to get some space. This happens often.
Great difficulty trusting people and themselves. Early trust may have been shattered by people who were close to you.
Sensitivity to criticism or rejection.
Feeling of "needing" someone else to survive
Heavy need for affection and reassurance
Some people with BPD may have an unusually high degree of interpersonal sensitivity, insight and empathy
9. Transient, stress-related paranoid ideation or severe dissociative symptoms
This means feeling "out of it," or not being able to remember what you said or did. This mostly happens in times of severe stress.
Miscellaneous attributes of people with BPD:
People with BPD are often bright, witty, funny, life of the party.
They may have problems with object constancy. When a person leaves (even temporarily), they may have a problem recreating or remembering feelings of love that were present between themselves and the other. Often, BPD patients want to keep something belonging to the loved one around during separations.
They frequently have difficulty tolerating aloneness, even for short periods of time.
Their lives may be a chaotic landscape of job losses, interrupted educational pursuits, broken engagements, hospitalizations.
Many have a background of childhood physical, sexual, or emotional abuse or physical/emotional neglect.