«It’s just hormones» – is it, though?
„Are you on your period or something?“ – „Before my period I’m simply not myself.“ – „Maybe I’m just imagining it.“
Few clichés are as stubborn as this one: women are «moody» before their period, and that explains everything. At the same time, there are women for whom the days before menstruation are a genuine crash every single month – and who hear for years: «Everyone has that.» Both cannot be true. So here is a fact check – without trivialising and without dramatising.
I write this as a coach, not as a doctor: here is the research, here is the medical boundary, and here is what coaching can do. The basics on cycle, emotions and partnership are in the post Menstruation, Emotions and Relationships – I won’t repeat them here.
What the research shows about cycle and mood
Surprisingly little of what «everyone knows» holds up. A systematic review by Sarah Romans and colleagues (Gender Medicine, 2012) analysed 47 studies in which mood was not recalled afterwards but recorded daily and prospectively across at least one full cycle – in women who were not seeking treatment for symptoms. The result: only around 15 percent of the studies found the classic pattern of «low mood only before the period», and almost 40 percent found no link at all. The authors’ conclusion: the data do not support a general «premenstrual negative mood syndrome».
A second, well-documented finding: asked retrospectively («How do you typically feel before your period?»), women report considerably more symptoms than their own daily records for the same period show. Marván and Cortés-Iniestra (Health Psychology, 2001) added a twist: the more strongly a woman believed that «most women have PMS», the wider that gap was. Expectations colour memory – a normal memory effect, not imagination.
Does that mean there is no link? No. Newer diary studies with hormone measurements do find effects, for example of progesterone on energy, sleep and mood – but they are small, inconsistent and highly individual. Put honestly: cycle-related fluctuations exist, they are moderate for most women, and «the hormones» rarely explain an entire conflict. Anyone who reflexively points at the cycle after an argument usually has a communication problem, not a hormone problem.
PMS: common, real – but not «everyone»
Premenstrual syndrome (PMS) is real. According to University Hospital Zurich, more than 20 to 30 percent of women of reproductive age are affected – in Switzerland at least 360,000 women between 15 and 50. Around 80 percent report some premenstrual symptom, mostly without meaningful impairment; apply strict criteria and the share with clinically significant PMS shrinks to a fraction.
So PMS is common enough that nobody needs to be ashamed of it – and rare enough that «everyone has that» does not work as an answer.
PMDD: when it is more than bad days
Premenstrual dysphoric disorder (PMDD; PMDS in German) is something different from severe PMS: since 2013 a diagnosis in its own right in DSM-5, and listed in the WHO’s ICD-11 under code GA34.41. The core criteria:
- At least five of eleven symptoms in the week before menstruation, including at least one core symptom: marked irritability, mood swings, depressed mood or tension/anxiety.
- Symptoms improve within a few days of the period starting and are minimal or absent in the week after. This symptom-free window is what distinguishes PMDD from a depression that merely gets worse before the period.
- They clearly interfere with work, relationships or daily life.
- They must be confirmed by prospective daily ratings over at least two cycles – not by looking back.
How many women does this affect? A meta-analysis from the University of Oxford (Reilly and colleagues, Journal of Affective Disorders, 2024) covering more than 50,000 participants from 44 studies found around 1.6 percent confirmed diagnoses in the general population and around 3.2 percent provisional ones (without two-cycle records). The frequently quoted range of 3 to 8 percent mostly rests on questionnaires without diaries. University Hospital Zurich estimates roughly 40,000 women affected in Switzerland. Small in percent – but every one of them loses a week, month after month.
Important: PMDD is treatable. There are well-studied medication options (a 2024 Cochrane review of 34 trials confirms that SSRIs work, with moderate certainty of evidence) and psychotherapy, such as cognitive behavioural therapy. Which of these fits you is something to work out with your gynaecologist or GP – not with a blog, and certainly not with a coach.
Where the medical boundary runs
- If every month, in the week before your period, you fall into a hole that noticeably restricts your life, that is a matter for your gynaecologist or GP. Bring a cycle diary covering two cycles.
- If the dark days do not disappear after the bleeding starts, that points more towards depression or an anxiety disorder – which belongs in psychotherapeutic or psychiatric hands. More in Coaching vs. Therapy.
- In perimenopause, mood problems can appear or intensify; that too needs medical assessment, not «coaching».
- If thoughts of not wanting to live any more surface: talk to someone, today. In Switzerland, Die Dargebotene Hand is available around the clock on 143; in an emergency call 144.
Coaching replaces neither diagnosis nor treatment – it can accompany them, see Why It’s Okay to Seek Help.
What coaching can do: observe instead of judge
One tool has proven itself in coaching – and it is exactly what medicine asks for anyway: cycle tracking as self-observation. One minute a day for two or three cycles – no app interpretation, no forecast, just data. It delivers three things:
- A reality check. Many people are surprised at how far records and memory diverge – in both directions. Some discover that the «bad days» are not cyclical at all but coincide with work peaks or lack of sleep (see Sleep and Mental Health). Others see a clear pattern in black and white for the first time – and take it to their doctor.
- Planning instead of surprise. If you know your threshold for irritation is lower on certain days, you don’t schedule the difficult conversation right there. That is self-leadership, not an excuse.
- Less self-condemnation. The inner comment «I’m impossible» becomes «cycle day 25, little sleep, that explains a lot». How that works is in Self-Compassion Instead of Self-Criticism.
🟢 Tip: Note just three numbers from 0 to 10 each day – mood, energy, irritability – plus the cycle day. After two cycles, draw a curve. Nothing more: people who track too much stop after a week.
Two limits come with it: tracking is not a diagnosis – the pattern belongs in medical hands. And the cycle is not an excuse – it may explain why something is harder, not that responsibility disappears.
Relationships and communication
«Are you on your period?» ends almost every argument, because it devalues the other person. «I notice I’m thinner-skinned this week – I need a bit more quiet» opens one. Speaking about yourself opens; diagnosing the other person closes. Two sentences that work:
- From her: «This has to do with my cycle and the issue is still real. Can we talk it through calmly at the weekend?»
- From him or her: «I take you seriously. Tell me what you need right now – closeness or space?»
Conclusion
The link between cycle and mood is real, but smaller, more individual and less consistent than the cliché claims – and retrospective self-assessments overstate it. PMS is common; PMDD is rare, serious and treatable. The path from suspicion to clarity is the same in both cases: write down two cycles honestly instead of guessing. What comes out belongs either in medical hands or in your own self-leadership – usually both.
Would you like to understand your patterns instead of guessing?
In coaching we set up your tracking so you actually stick with it, read the curve together, and clarify what belongs to your doctor and what you can shape yourself – in everyday life and in your relationship.
Schedule a free introductory session now
Your progress is my joy.
