The four vital signs of your cycle

Major medical bodies describe the menstrual cycle as a vital sign — something that reflects overall health, like blood pressure or heart rate.

Four parameters carry most of the signal: how often your cycle comes (frequency), how consistent it is cycle-to-cycle (regularity), how many days you bleed (duration), and how heavy that bleeding is (flow volume).

This app treats those four as the spine of your data. Everything else — symptoms, temperature, lifestyle — hangs off them.