PCOS/PMOS: It’s Not Stress — It’s Physiology
(PART II: nervous system + stress response)
If Part I was about the hormonal and metabolic picture of PCOS/PMOS, Part II is about the piece that tends to get dismissed.
Women with PCOS/PMOS are often described as more emotional.
More irritable.
More anxious.
More affected by the weeks before their period than seems proportionate.
They’re often told this is just how they are.
That they need to manage stress better.
Or, more bluntly, not to be so dramatic.
The reality is more interesting—and more validating.
Quick reminder: PMOS (Polyendocrine Metabolic Ovarian Syndrome) is the updated term for what has traditionally been called PCOS.
The shift reflects what many clinicians already recognize—this is a hormonal and metabolic condition affecting multiple systems, not just the ovaries.
In Part I, we broke down that bigger picture.
(Missed Part I? Read it here!)
PMDD & PMOS: A COMMON OVERLAP
Premenstrual dysphoric disorder (PMDD) involves significant mood changes in the one to two weeks before menstruation:
– irritability
– anxiety
– depression
– emotional volatility
These symptoms typically resolve once the period begins.
It’s distinct from typical PMS in both intensity and predictability.
Women with PMOS have higher rates of PMDD than the general population.
This isn’t a coincidence.
Both conditions involve heightened sensitivity to normal hormonal fluctuations.
Hormone levels themselves are usually within expected ranges.
The difference is in how the body—and brain—responds to those shifts.
WHY THE RESPONSE IS AMPLIFIED
A key piece is allopregnanolone—a neurosteroid made from progesterone.
In a typical cycle, it has a calming effect on the nervous system during the luteal phase.
In women with PMDD and/or PMOS, the brain responds differently.
Instead of producing calm, this same hormonal shift can trigger:
– increased anxiety
– irritability
– a heightened stress response
The result:
The phase of the cycle that should feel more settled can instead feel like the most difficult.
THE HPA AXIS & STRESS RESPONSE
This sensitivity doesn’t just show up around the menstrual cycle.
Many women with PMOS also have a more reactive stress response overall.
The HPA axis—the communication loop between the brain and adrenal glands—regulates cortisol.
In PMOS, this system can be more easily activated and slower to settle.
Cortisol rises more quickly.
It stays elevated longer.
And elevated cortisol can increase androgen production, amplifying symptoms further.
HOW THIS CAN SHOW UP
This pattern can look like:
-Feeling overwhelmed by things that typically wouldn’t be stressful
-Difficulty recovering after stress (an “emotional hangover”)
-Anxiety that feels physical (racing heart, tight chest, restlessness)
-Mood shifts tied closely to sleep, meals, and stress levels
-Cycles becoming more irregular during stressful periods
None of this reflects weakness.
It reflects a system operating under a higher baseline load.
IT’S NOT A CHARACTER FLAW. IT’S PHYSIOLOGY.
One of the most important things to understand:
The emotional symptoms of PMOS are not personality traits.
They’re not overreactions.
They’re not a lack of resilience.
They are predictable outputs of a more sensitive hormonal and nervous system.
In many cases, that system is:
More reactive to hormonal shifts
More responsive to stress
Carrying a higher inflammatory load
In simple terms:
It’s working harder.
WHY THIS MATTERS FOR TREATMENT
When we address the underlying physiology —
-blood sugar regulation
-androgen balance
-adrenal support
— the emotional picture often improves as well.
Not because the emotions aren’t real.
But because the system driving them has shifted.
If any of this resonates—whether for yourself or someone you love—here are a few places to start:
-Track your cycle and mood together for 2–3 months
-Prioritize blood sugar stability (regular meals, 20–30g protein per meal, limit refined carbs)
-Protect sleep—this is when the stress response resets
-Don’t try to manage the emotional piece in isolation
The right support—hormonal, nutritional, or otherwise—can change the terrain significantly.
If you’re in Oregon or Utah and want to explore what’s going on hormonally, I’d love to help.
This is exactly the kind of work my practice is built around.
Warmly,
Dr. Krista
Olive Says
Sensitive to everything?
A drama queen?
Guilty as charged.
I treat a delayed dinner like a personal betrayal.
My humans call it drama.
I call it elevated cortisol and a very responsive HPA axis.