How is someone determined to have bipolar disorder, what does it consist on?

Diagnostic Interview. This is a very broad question...Too broad to be answered with any brief summary here. Generally speaking, bipolar disorder is diagnosed by a clinician familiar bipolar disorder eliciting those signs and symptoms during a clinical interview. There are no blood tests or scans that necessarily make the diagnosis. For more information, try: http://www. Ncbi. Nlm. Nih. Gov/pubmedhealth/pmh0001924/.
It's complicated. If by 'bipolar' you mean moody, I am sure your friends and family can tell you. If instead you mean having the diagnosable serous mental illness called bipolar disorder, it is best to get a psychiatric evaluation ad bipolar disorder is easy to both under- and over- diagnose. Hope this helps. Good luck!