I was able to work (barely) during my manic episodes until I went psychotic and had to be hospitalized.

For be I know it's mania when I start having weird thoughts, like I tend to believe I have magical healing powers when I'm manic. I only count it as hypomania when im feeling great but my feet are still attached to the ground. Like I'm still logical and can keep my stranger or more harmful impulses under control. When I can't stop myself from screaming in irritation or driving 100mph or singing/dancing in front of my students then I know it's beyond hypomania.