How does hyperthyroidism affect a woman entering menopause, who still has a regular menstrual cycle?

All the usuals. Hyperthyroidism in a premenopausal woman may cause high heart rate, palpitations, hot flashes (so may be difficult to distinguish from menopause), shakes/tremors, sweats, and diarrhea.
If treated. Then it will not, if not treated then get it treated. Hypothyroidism will slow down or stop the periods; hyperthyroidism generally gets treated b/c people are symptomatic. Question is, is it treated?