Informally I will tell someone "I'm bipolar" such as a close friend, but if it's to a professional such as a doctor or a prof I trust I will say "I am diagnosed with schizoaffective disorder bipolar type". I'm not open to my true diagnoses since it has a lot if bad stigma attached to it. Saying that I'm bipolar is easier for people to understand and still view me the same for the most part.