Does my friend have bipolar disorder? And what should I do?

My best friend of two years has always had horrible migraines and has been on some sort of medicine. Recently, (about two months ago) her mom took her off her medicine. She also has a father who has bipolar disorder.
Yesterday, she was laughing hysterically (over something not that funny) and was doubled over laughing and I went to grab her and she flipped up and around right as i put my hand down and I guess my nail must have scratched her (I didnt feel a thing) but she started FREAKING out at me, cussing me out and calling me a ***** and things in the middle of our English class. I clearly had no clue what was going on and as she was insulting me I got mad and we had a fight.
Later I tried to make amends and she insisted on freaking out AGAIN, cussing me out again and actually slammed a locker on my hand.
My BEST friend of almost two years, and we have never fought like that before. She just suddenly snapped. I want to know if it could be bipolar disorder. This behavior scares me.

This behaviour is in need of a mental health evaluation. Speak to her mom and urge she get her the help. Your friend can be at great risk if nothing is done. As for Bipolar, possibly, but it needs to be diagnosed by a doctor. There can be other reasons for such behaviour unknown to you. She needs help and needs it now.

I think you should stay away from her.
This friendship will not help you.

It's possible. Bipolar disorder (previously called manic depression) is characterized by extreme highs and lows.

You may wish to ask your friend if she's been feeling alright lately, been depressed, etc., and ask if there's anything you can do.

Bipolar disorder is a manageable condition, and being a friend to this person can help them through what will surely be a difficult time.

my son has bipolar disorder and some of the behaviours you are noticing are sometimes part of bipolar they are up one minute and down the next....however i am not qualified to make a diagnosis. the other key is that it runs in families. so yes its possible. dont give up on the friendship cause what they do is very hard for them to control. see if her parents are aware of this behaviour and maybe suggest an evaluation from a qualified doctor...good luck

It doesn't sound like bi-polar to me, but if she has just come of meds it's possible she may have mood swings for a while whilst her body chemistry sorts itself out. I would keep an eye on the situation, you know that bi-polar is swinging between periods of elation and severe depression, so just watch for signs of depression and lack of confidence in situations where she shouldn't feel that way. It would be a good idea to let her parents know of your concerns, but i would broach the subject carefully, they may be defensive about such things

It may very well be bipolar. However, I am not a doctor. There is a .gov site that has great info on the subject. I can't remember the name though. I had used the site as a reference in a paper.

From your description I think there's a very good chance that you are right about her possibly having a form of Bipolar Disorder. Other possibilities are drug abuse of stimulants such as crack cocaine or amphetamines, or a combination of Bipolar Disorder and drug abuse. Very much less likely are a number of medical problems that can cause behavioral symptoms, such as overactive thyroid or brain tumor.

She needs to be seen by a psychiatrist, but it's unlikely that she'll respond very well if you make that suggestion. She just MIGHT be able to accept this kind of recommendation from you if you wait until she seems to be at a period of relative stability, and you talk to her about some of the behaviors you have observed. Unfortunately, all too often, because people with these kind of problems are unwilling to seek help, and they don't end up getting help until they end up hurting someone, hurting themselves, or breaking the law, at which point they can be committed for involuntary psychiatric hospitalization.