You don’t have to say the word bipolar if you don’t want to. You can just mention that you have a medical condition that sometimes affects your energy or focus. If you need accommodations, you can ask for them without going into details. Something like “I occasionally need some flexibility for medical reasons” is enough. Most employers don’t need to know more, just that you can do the job with a few adjustments if needed.

If things get tough, you can always take a leave of absence when necessary. You don’t have to justify every bad day or explain yourself to anyone. In the end, what matters is that you can do your job without feeling exposed.