If the days before your period reliably bring you to your knees — not just irritable, but unable to function — this is worth taking seriously.
PMS vs PMDD. Premenstrual syndrome (PMS) is common and usually manageable: mood dips, bloating, sore breasts, cravings in the luteal phase (the week or so before your period). PMDD is more severe and centres on mood: intense depression, anxiety, irritability or anger, and a sense of being out of control, severe enough to disrupt work, relationships, and daily life. The hallmark of both is timing — symptoms appear in the luteal phase and lift within a day or two of bleeding starting.
Why it happens. It's not that women with PMDD have abnormal hormone levels — it's an unusually strong sensitivity to the normal hormonal shifts of the cycle, affecting mood-regulating brain chemicals like serotonin.
How to know. The single most useful step is tracking symptoms across two or three cycles — noting mood and physical symptoms daily. A clear pattern (bad in the luteal phase, relief at menstruation) is what distinguishes PMDD from other mood conditions, and it's exactly what a clinician needs to see.
What helps:
If your premenstrual phase regularly feels unbearable, track it and bring the pattern to your doctor. Relief is possible.
What's the difference between PMS and PMDD?
PMDD is a severe, mainly mood-based form of premenstrual distress that disrupts daily life, whereas PMS is milder and more manageable. Both ease once the period starts.
How is PMDD diagnosed?
By tracking symptoms across two to three cycles to confirm the luteal-phase pattern, then discussing it with a clinician.
Keep reading: Your cycle, phase by phase · Why anxiety spikes in perimenopause · Take the free Hormone Quiz