At some point in her late thirties or early forties, a woman begins to notice that something has shifted.

By Dr. Diego Schmidt · 10 min read

It might be her sleep — disrupted in ways it never was before, and unrestorative in ways that simple tiredness does not quite explain.

It might be her mood — a low, unfamiliar irritability that sits quietly underneath the day.

It might be the weight around the middle that appeared without any meaningful change in diet.
The brain fog that descends mid-afternoon.
The anxiety that doesn’t quite match her life.

If she brings this to a doctor, she is often told one of two things:

• Her hormone levels are “normal for her age”, or
• She is perimenopausal and receives a prescription.

Neither answer provides what she actually came for — a clear understanding of what is happening in her body.

What Perimenopause Actually Is

Perimenopause is not the beginning of the end of female hormonal health.

It is a transition — typically spanning four to ten years before the final menstrual period — during which the relationship between oestrogen and progesterone begins to shift.

These shifts can have profound whole-body effects.

Contrary to popular belief, the first hormonal change is usually not a drop in oestrogen.

The first change is often progesterone insufficiency.

Progesterone — produced after ovulation — acts as the calming, regulating counterpart to oestrogen. It plays an important role in:

• Supporting healthy sleep patterns
• Reducing anxiety
• Moderating inflammation
• Stabilising mood

When ovulation becomes irregular, progesterone levels begin to fall — and often inconsistently.

The result is what many clinicians refer to as oestrogen dominance. Not because oestrogen levels are necessarily high, but because progesterone is no longer present in sufficient amounts to balance it.

This is why many perimenopausal women describe feeling “wired and tired” at the same time.

It explains why:

• Sleep is often the first thing to change
• Anxiety can feel physical rather than psychological
• The body feels overstimulated but exhausted

What the Tests Often Miss

Standard hormonal testing during perimenopause can be unreliable.

Levels of FSH and oestradiol fluctuate dramatically:

• From cycle to cycle
• Sometimes even from day to day

A single blood test that comes back “normal” often reveals very little about what hormones are actually doing across an entire month.

What matters more is the pattern.

The relationship between hormones over time, combined with the clinical picture a woman is experiencing.

In medicine, this is known as the presenting history — and it is often one of the most important diagnostic tools available.

A woman describing symptoms consistent with progesterone insufficiency deserves a clinician who recognises that pattern and takes her experience seriously — not one who relies only on lab reference ranges.

The Thyroid Connection

Perimenopause and thyroid dysfunction are closely connected — and frequently confused with one another.

Conditions such as subclinical hypothyroidism and autoimmune thyroid disease, particularly Hashimoto’s thyroiditis, often appear during the same life stage.

These conditions share many of the same symptoms:

• Persistent fatigue
• Weight fluctuations
• Mood instability
• Brain fog
• Temperature sensitivity
• Sleep disturbances

Standard thyroid screening typically measures TSH alone, which is a signal from the pituitary gland.

However, TSH can appear normal even when the thyroid itself is struggling.

A more complete thyroid assessment may include:

• Free T3
• Free T4
• Thyroid antibodies
• A broader view of the metabolic and hormonal context

Many women live with an undiagnosed thyroid condition for years before it is properly identified.

Others are reassured that their tests are normal, while the symptoms that brought them to the clinic remain unresolved.

What This Transition Actually Asks For

When understood correctly, perimenopause is not a disease that needs to be managed.

It is a biological transition that requires support.

The female hormone system during this stage is not broken. It is reorganising.

The symptoms that appear are often the body communicating that the conditions for that transition are not ideal.

In many cases, underlying factors may include:

• Adrenal stress
• Metabolic imbalance
• Nutritional deficiencies
• Increased inflammatory load

When these areas are addressed — when the whole picture is understood — the transition can change significantly in quality.

Not eliminated.
Not suppressed with medication alone.
But navigated with greater understanding and far less suffering.

That is what thoughtful women’s medicine during this stage should look like.

Not a prescription written in the first ten minutes.

But a genuine effort to understand what is happening — and to help the body find its way through the transition with the support it needs.