It's odd that a psychiatrist wouldn't know racing thoughts as a common symptom of hypomania, mania, or mixed states of bipolar. I do know, however, that "racing thoughts" can also be present in some forms of anxiety.

I guess I'd assume that perhaps a doctor may assume anxiety if few (if any) other symptoms of hypomania, mania, or mixed states are present. Even anxiety itself can be part of bipolar disorder for many, or at least a mixed episode. Also, anxiety can be a separate issue for a person with a bipolar disorder diagnosis. We may be dealing with anxiety while our moods are stable. Anxiety forms can also exhibit differently, at times. For example, it can bring irritation and/or other reactions we may not even realize at first. For example, I start grinding my teeth or picking at my skin on my fingers or holding my breath sometimes when I'm stressed, but I'm not exhibiting any clear fear, dread, or worry that are more "stereotypical" anxiety symptoms. Racing thoughts can be another of many examples. I think anxiety and bipolar-induced racing thoughts have similarities, but also differences.

I'm not saying you never get hypomanic or aren't, but if racing thoughts are the only symptom you currently have, maybe it's anxiety...or something else (too much sugar or caffeine, hormonal fluctuations, other). Do discuss any other feelings with your doc, including physical ones.