What Is Perimenopause? The Real Definition Nobody Told You About

You are not falling apart.

You are not lazy. You are not "just stressed." And you are absolutely not imagining it.

If you are in your late 30s or 40s, and something feels deeply, undeniably off — your energy is gone, your weight won't shift no matter what you do, your sleep is broken, your moods are unpredictable, and you quietly feel like a stranger in your own body — there is a very real, very physiological reason for all of it.

It is called perimenopause.

And the version you have probably been told about — if you have been told anything at all — is incomplete. Possibly even wrong.

Today, we are going to change that.

The Definition You Were Given (And Why It's Not Enough)

Most women hear "perimenopause" described as simply the transition period before your periods stop. A kind of hormonal waiting room. A few irregular cycles, maybe some hot flashes, and then menopause arrives.

That definition is technically accurate. It is also almost completely useless.

Here is what they don't tell you:

Perimenopause can begin in your mid-to-late 30s. It can last 10 to 15 years. It does not begin with hot flashes — it begins with subtle, creeping changes that your doctor may dismiss, and that you may blame on stress, overwork, or simply "getting older."

It is, in every sense, a full hormonal transition — and it affects every system in your body.

The Real Definition of Perimenopause

Perimenopause is the phase of hormonal transition that precedes menopause. It is characterised by fluctuating and eventually declining levels of your reproductive hormones — primarily progesterone and oestrogen — as your ovaries begin to wind down their egg-producing capacity.

But here is what makes it so disorienting: it is not a linear, predictable decline. It is chaotic. Your hormones do not simply drop steadily downward. They surge, plummet, spike, and fluctuate — sometimes wildly — from one month to the next.

Experts call this "hormone chaos." And that phrase captures it perfectly.

One month you may feel fine. The next, you are lying awake at 3am, snapping at your partner, unable to shift the belly fat that appeared seemingly overnight, wondering what on earth is happening to you.

That is perimenopause.

When Does Perimenopause Start?

This is one of the most important — and most misunderstood — facts about perimenopause: it often starts earlier than you think.

While the average age of menopause (the point at which your periods stop for 12 consecutive months) is around 51 or 52, perimenopause typically begins 10 to 15 years before that. For many women, that means changes are beginning in their late 30s to early 40s.

Women often come to practitioners saying, "Something isn't right. I can't keep excusing these symptoms as stress or overwork anymore. I don't feel like myself." And they are in their early 40s — sometimes even their late 30s.

The reason perimenopause is so often missed at this stage is that women are still having regular periods, still ovulating (some of the time), and still producing oestrogen. Standard blood tests may look "normal." But something has shifted. And that something is usually progesterone.

Why Progesterone Drops First — and Why It Matters So Much

Here is a piece of information that will explain a great deal of what you are feeling.

Progesterone is typically the first hormone to decline in perimenopause.

As your ovaries begin to receive signals that egg production is winding down, you start to have what are called anovulatory cycles — cycles where you do not ovulate. Since progesterone is produced primarily by the shell of the released egg (the corpus luteum) after ovulation, no ovulation means little to no progesterone produced in that cycle.

Progesterone is not simply a reproductive hormone. It is a neurosteroid — meaning it has a profound effect on your brain and nervous system. It works closely with GABA, the calming neurotransmitter that helps you feel relaxed, sleep deeply, and manage stress with ease.

When progesterone drops, GABA support drops with it. The result?

• Sleep becomes broken and unrestorative

• Anxiety arrives seemingly out of nowhere

• Stress tolerance falls through the floor

• Mood stability becomes fragile

• You feel overstimulated, reactive, and unlike yourself

Meanwhile, oestrogen in early perimenopause may still be robust — and without progesterone to balance it, you can find yourself in a state of oestrogen dominance: heavier periods, bloating, breast tenderness, migraines, and weight gain around the hips and abdomen.

This is not weakness. This is not a mental health problem. This is your hormonal landscape changing — and your body asking for support.

The Symptoms Nobody Connects to Perimenopause

One of the most extraordinary things about perimenopause is how many symptoms it produces that women — and their doctors — never connect to hormones at all.

You may have heard that perimenopause means hot flashes and night sweats. And yes, those are symptoms. But there are over 35 recognised symptoms of perimenopause — and recent research has even added "not feeling like myself" as a legitimate, clinical symptom.

Here are the ones that most often go unrecognised:

Physical symptoms:

• Weight gain despite eating well and exercising

• Belly fat that appeared suddenly, seemingly from nowhere

• Constant fatigue that sleep does not fix

• Waking at 3am and being unable to fall back asleep

• Afternoon energy crashes

• Brain fog and difficulty concentrating

• Bloating and digestive changes

• Constipation

• Joint pain and feeling "inflamed"

• Low libido

Emotional and cognitive symptoms:

• Anxiety — especially new-onset anxiety with no clear cause

• Irritability and snapping at the people you love

• Low mood or emotional flatness

• Brain fog and memory lapses

• Feeling emotionally fragile or easily overwhelmed

• A deep, unsettling sense of not feeling like yourself

Cycle changes:

• Irregular periods — some heavier, some lighter, some late, some early

• Worsening PMS or premenstrual symptoms

• Shorter or longer cycles

• Cyclical symptoms that are worse in the second half of your cycle (luteal phase)

If any of this resonates, you are not imagining it. These are real, physiological symptoms with a hormonal root cause.

Why Nothing Seems to Work Anymore

Here is the truth that the diet industry, the fitness industry, and much of mainstream medicine are not telling high-performing women in their 40s:

The strategies that worked in your 30s will not work in the same way now. This is not a willpower problem. This is a physiology problem.

In perimenopause, your body's relationship with cortisol, insulin, and your sex hormones changes profoundly. Chronically elevated cortisol — the stress hormone — can store fat preferentially in your abdomen, disrupt your sleep, drive cravings for sugar and carbohydrates, and actively suppress your progesterone and oestrogen production.

For the high-achieving woman who responds to challenges by pushing harder — more exercise, less food, more supplements, more caffeine — this becomes a vicious cycle. You push harder. Your cortisol rises. Your hormones destabilise further. Your body holds onto fat, resists sleep, and sends you crashing.

Your body is not broken. It is communicating. And it is asking for a fundamentally different kind of support.

"My Blood Tests Came Back Normal" — What That Really Means

This is one of the most common — and most heartbreaking — experiences for women in perimenopause.

You go to your GP. You explain your symptoms. Blood is taken. Results come back "within normal range." You are told nothing is wrong.

But you know something is wrong. Because you feel it every single day.

Here is why this happens: standard blood tests are a snapshot. They measure your hormone levels at a single point in time, and they compare them against a "normal" range that is incredibly broad and does not account for where you are in your cycle, how your hormones are fluctuating, how your body is metabolising those hormones, or what your cortisol is doing throughout the day.

A woman in early perimenopause can have hormone levels that appear perfectly normal on a standard blood panel — and still be experiencing significant hormonal disruption.

This is not gaslighting. This is a gap in conventional testing. And it is a gap that comprehensive functional hormone testing is specifically designed to fill.

Looking Under the Hood: The DUTCH Comprehensive Hormone Test

If you want to truly understand what is happening in your hormonal landscape — not just a superficial snapshot, but a full, detailed picture — the DUTCH Comprehensive Hormone Test is one of the most powerful tools available.

Unlike a standard blood test, the DUTCH Test (Dried Urine Test for Comprehensive Hormones) measures:

• Your sex hormones — oestrogen, progesterone, and testosterone

• How your body is metabolising those hormones — including oestrogen detoxification pathways

• Your cortisol and cortisone patterns across the day and night (giving a picture of your stress system and HPA axis function)

• Melatonin — the hormone that governs your sleep

• Key organic acids that reflect neurotransmitter function and cellular energy production

The DUTCH Test does not just tell you what your hormone levels are. It tells you what your body is doing with them. It shows patterns over time, not just a single moment. And it opens the door to targeted, personalised support — rather than guessing.

At My Functional Medicine Clinic, we use the DUTCH Comprehensive Hormone Test as a cornerstone of our approach to perimenopause care. Because you deserve answers. Not assumptions.

→ Order your DUTCH Comprehensive Hormone Test here and get the clarity you have been looking for.

You Don't Have to Keep Guessing

Perimenopause is not just the beginning of the end of your reproductive years. It is a major hormonal transition that deserves to be understood, supported, and taken seriously.

You are not "too young" for perimenopause. Your symptoms are not in your head. And the answer is not to push harder, eat less, or simply endure.

The answer is to understand what is happening in your body — at the root level — and to work with it rather than against it.

If you are ready to stop guessing and start getting real answers, I would love to support you.

→ Book a Clarity Call at myfmclinic.com/appointment

In this call, we will talk through what you are experiencing, explore whether a DUTCH Test is the right next step for you, and map out a path forward that is built around your unique hormonal picture — not a generic plan.

You do not need more discipline. You need the right information. And you need someone in your corner who understands exactly what your body is going through.

I am here. Let's figure this out together.

Written by Ingrida Makaraite-Girdvaine, Functional Medicine Practitioner | myfmclinic.com

Frequently Asked Questions About Perimenopause

How do I know if I am in perimenopause? Perimenopause is typically a clinical diagnosis based on your symptoms, cycle changes, and age — rather than a single definitive test. Common early signs include worsening PMS, irregular cycles, sleep disruption, new-onset anxiety, unexplained weight gain, and fatigue. If you are in your late 30s or 40s and something feels "off," perimenopause may well be a factor.

Can you be in perimenopause and still have regular periods? Yes. Many women in early perimenopause still have relatively regular cycles. The changes often show up first in the quality of the cycle — worsening PMS, heavier or lighter bleeding, shorter or longer cycles — rather than outright irregularity.

What is the difference between perimenopause and menopause? Menopause is defined as 12 consecutive months without a period. Everything before that final period — the years of hormonal transition — is perimenopause. Perimenopause can last 10 to 15 years.

Can a blood test diagnose perimenopause? Standard blood tests can support a diagnosis but are often unreliable in early perimenopause because hormone levels fluctuate so much. A comprehensive functional hormone test like the DUTCH Test provides far more detailed and useful information for women in this transition.

Is perimenopause why I cannot lose weight? Quite possibly, yes. The hormonal shifts of perimenopause — falling progesterone, fluctuating oestrogen, and rising cortisol — all have a significant impact on metabolism, insulin sensitivity, fat storage, and appetite. Weight gain during perimenopause, particularly around the abdomen, is a real and physiological phenomenon — not a failure of willpower.