The DSM differentiates hypomania and mania by duration and severity. It says it is hypomania if "the episode is not severe enough to cause marked impairment in social or occupational functioning, or to necessitate hospitalisation, and there are no psychotic features.”

I can relate to your symptoms with both hypo and manic episodes. My family can tell pretty much immediately if I'm getting hypo. For me, hypomania is woooonderful, but when I'm manic my brain is totally out of control. My thoughts are racing so fast that I feel like steam should be shooting out of my ears. I can't be reasoned with and I do things that wreck my life. Just my experience.