Hey there Christina

You know...I have wondered this same thing about myself.  It seems that Bipolar Disorder is on a bit of a continuum and now they have different designations as in Bipolar I and II. 

Honestly...the best way you are going to know is to have a therapist or psychiatrist make that diagnosis.  If you were to treat it with meds...getting the official diagnosis is the only way to do that. 

I am going to give you some information in the meantime, however.  If you haven't visited the Bipolar site here on Health Central...maybe go and take a gander at what information they have there.

Health Central also does have a test you can take to give you more of an idea if you are dealing with straight up depression or is it more Bipolar Disorder.

What does your gut tell you?  Do you experience a lot of extreme highs and lows?  Is the rollercoaster ride of emotions disabling or affecting your day to day functioning?  If the answer is yes then maybe it is time to see a therapist to check things out.

I wish you the best of luck and thank you for your question.