Overview
Overview
The menstrual cycle is a recurring series of physiological changes occurring in the female reproductive system, averaging 28 days (normal range: 21–35 days).
The menstrual cycle is a recurring series of physiological changes occurring in the female reproductive system, averaging 28 days (normal range: 21–35 days). It is regulated by the hypothalamic-pituitary-ovarian (HPO) axis and has two simultaneously occurring cycles: the ovarian cycle (follicular → ovulation → luteal) and the uterine cycle (menstrual → proliferative → secretory). Understanding the menstrual cycle is foundational to antepartum assessment, fertility counseling, and reproductive health nursing across all practice settings.