condition-guides

PCOS and Period Irregularity: What Changes and How to Track

PCOS disrupts ovulation, making periods unpredictable in timing and flow. This guide explains the physiology and what to track for clinical monitoring.

What PCOS Actually Does to Your Cycle To understand why PCOS disrupts periods, it helps to know what a regular cycle requires. Each cycle involves a coordinated hormonal sequence. FSH from the pituitary stimulates follicle development. One follicle becomes dominant and releases an egg. LH surges to trigger that release. The remaining corpus luteum produces progesterone, which stabilizes the uterine lining. When progesterone declines, the period begins. PCOS interferes at the follicle development stage. Elevated androgens, often amplified by elevated insulin, prevent any single follicle from becoming dominant. Multiple follicles begin to grow and then stall. Without a dominant follicle, there is no ovulation, no corpus luteum, and no progesterone surge and decline. The cycle does not complete normally. This guide is for educational purposes only and is not a substitute for medical advice. What Your Bleeding Pattern May Look Like Because PCOS disrupts ovulation rather than menstruation itself, the bleeding pattern is variable and depends on what happens to the uterine lining in the absence of regular progesterone cycling. Long cycles and infrequent periods Without ovulation triggerin