Period phase could skew heart test results, study finds

This study looked at 47 premenopausal women to see if the phase of their menstrual cycle changes the results of an exercise treadmill test (a heart stress test). Researchers compared test results from the early and late follicular phases, when estrogen levels are low and high, to understand why women often get false positive results. The goal was to learn more about the biological causes behind these misleading test outcomes.