When PMS Isn’t Just PMS: Understanding Hormonal Mood Shifts

Summary: Many women experience PMS, but when mood shifts feel overwhelming and disruptive, it could be PMDD—a severe, underdiagnosed condition. This article explains the difference, why it happens, and what can truly help.

Introduction

Snapping at your partner. Crying over something small. Feeling like a different person just before your period. It is a common notion known to women as well as men that females are prone to mood fluctuations in the days leading up to their period. But for some women, the turbulence is much more intense. It disrupts the workday, strains close relationships needlessly, and leaves them wondering, “Where’s all this rage coming from?”

This may not be “just PMS.” It could be something that often flies under the radar, only because not enough people are aware of it: a frequently underdiagnosed condition called Premenstrual Dysphoric Disorder (PMDD). PMDD is like the elder evil twin of PMS, emerges from the shadows in the second half of the menstrual cycle, and is still quite misunderstood, even by many healthcare professionals.

When premenstrual changes start to feel overwhelming, it may indicate something deeper than PMS—something important to acknowledge.

Being a psychiatrist who’s worked with many women experiencing period-related distress, and as someone who has gone through my fair share of premenstrual struggles, I write today to help unpack what really happens in PMDD, and what can help.

What’s Normal—and What’s Not?

PMS vs PMDD: Where is the Line?

PMS is familiar to most women. They are those days before your period when you might feel moody, tired, bloated, or just “off.” It often comes with breast soreness, irritability, and fatigue, and usually decreases once your period begins.

But PMDD is a different ballgame altogether. This is not about being a little snappy or teary. PMDD is a condition that can hijack your mind and emotions in the second half of your cycle.

Women with PMDD may experience:

Sudden anger or crying spells
Intense anxiety, panic, or hopelessness
Brain fog and trouble focusing
Disrupted sleep or appetite
A feeling of being out of control, or not quite yourself

The DSM-5, psychiatry’s official diagnostic manual, classifies PMDD as a cyclical depressive disorder. To qualify for diagnosis, these symptoms must occur in the two weeks before your period and meet a certain severity and pattern; at least five major symptoms, month after month¹.

Why Does This Happen?

Research indicates that PMDD is not caused by a hormone imbalance, but rather by an increased sensitivity to normal hormonal changes, particularly estrogen and progesterone².

During the luteal phase, changes in these hormones influence brain regions like the amygdala and prefrontal cortex, which regulate emotion, motivation, and stress³. There is also increasing evidence of circadian rhythm disruption in PMDD, which may explain why some women have more difficulty with sleep or energy fluctuations during this time⁴.

Tracking: A Crucial First Step

If you are unsure whether your symptoms are cyclical, try using apps like HealCycle, Clue, Flo, or a simple symptom diary. Femtech, meaning healthcare applications focused on female-specific health challenges, has been an emerging field in technology, with many apps already in the market and in development. What is crucial, though, is for these apps to be supported by a solid clinical & research evidence base that clearly defines the parameters to monitor and how to do so.⁵

Symptoms need to be logged across at least two menstrual cycles, noting mood, energy, sleep, focus, and physical signs.

This helps confirm patterns and opens the door for proper diagnosis and treatment. And if your symptoms persist all month, that’s worth looking into as well; conditions like depression, anxiety, or bipolar disorder can overlap with hormonal changes.

What Can Help?

Lifestyle Support

Sleep: Prioritise 7–9 hours, especially in the premenstrual week
Movement: Even gentle daily exercise helps regulate mood
Nutrition: Limit caffeine, sugar, and alcohol; focus on protein and B-vitamin-rich foods
Stress management techniques: Meditation, journaling, or recreation can reduce symptom intensity

Medication

SSRIs are first-line treatments for PMDD, often taken only in the luteal phase²
Hormonal contraceptives may help stabilise fluctuations, though they work better for some than others²
For severe cases, CBT (Cognitive Behavioural Therapy) or newer forms of emotion-focused therapy have shown benefit^6,7

Support Makes a Difference

Whether you live with PMS or PMDD, these are not “just mood swings.” They are biologically based, treatable, and real. Talk to a doctor who takes menstrual mental health seriously. Share symptom trackers with your provider.

Ask loved ones to understand the cyclical nature of what you’re experiencing. One of the best things a partner can do is just be there without judgment & opinion. Mostly, all a woman going through intense mood swings needs is validation of her unspeakable & often indescribable pain.

Final Thoughts

For too long, women’s mental health symptoms tied to the menstrual cycle have been dismissed. But PMDD is not a personality flaw or emotional weakness; it is simply a neurobiological condition, like any other, that deserves awareness, empathy, loving support, and scientific management.

References:

Premenstrual Dysphoric Disorder. StatPearls. NCBI Bookshelf. 2024.
https://www.ncbi.nlm.nih.gov/books/NBK532307/
MedlinePlus. Premenstrual Syndrome (PMS). U.S. National Library of Medicine. 2024. https://medlineplus.gov/premenstrualsyndrome.html
U.S. Office on Women’s Health. PMS and hormone sensitivity. 2024.
https://www.womenshealth.gov/menstrual-cycle/premenstrual-syndrome
ACOG. Guidelines on Management of Premenstrual Disorders. 2023.
https://www.acog.org/news/news-articles/2023/11/acog-releases-new-guidelines-on-management-of-premenstrual-disorders
Moglia ML, Nguyen HV, et al. Evaluation of Smartphone Menstrual Cycle Tracking Applications. Obstet Gynecol. 2016;127(6):1153-1160.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8162175/
Johns Hopkins Medicine. Premenstrual Syndrome and Mental Health. 2024.
https://www.hopkinsmedicine.org/health/conditions-and-diseases/premenstrual-syndrome-pms
Carlini, S. V., Lanza di Scalea, T., McNally, S. T., Lester, J., & Deligiannidis, K. M. (2022). Management of Premenstrual Dysphoric Disorder: A Scoping Review. International Journal of Women’s Health, 14, 1783–1801. https://doi.org/10.2147/IJWH.S297062