I can sort of relate to your dilemma. I also have bipolar 2 (diagnosed about a year ago), and was unsure for a long time whether to tell my boss. Although I try and keep my moods stable there, I do pose a challenge for her (and probably everybody else) at times. I did finally disclose to her that I was diagnosed and she was very understanding about it and actually can now "get" why I am so moody.
I don't know your specific work situation, of course, but I agree with seaturtle. There is no need to disclose any of your info to your boss if you are not comfortable with it. That is your personal business, and I actually applaud you for wishing to keep it that way. I sometimes wish I had done the same, because when I do lash out, I feel pretty "exposed."
And, you know, bipolar IS medical. And you're helping yourself to take care of it. No harm or shame in that.
I will be interested to hear what happens.