Perimenopause: the signs people miss.

Perimenopause is the transition to menopause, and it usually begins in your mid-forties. It rarely announces itself with hot flushes. The early signs are more often a cycle that shifts, sleep that breaks at 3am, new anxiety and brain fog, and they are commonly put down to stress instead.

Ask most people what menopause feels like and they will say hot flushes. But the years leading up to it often begin very differently, and much earlier than people expect. Many women spend years being told they are simply tired, stressed or anxious before anyone joins the dots.

First, the definitions

• Perimenopause is the transition. Ovarian hormone production becomes erratic, cycles change, and symptoms appear. It typically starts in the mid-forties but can begin earlier, and it commonly lasts several years, most often four to six.
• Menopause is a single point in time: your final period, which can only be confirmed once 12 months have passed without another one. The average age in Australia is around 51.
• Postmenopause is everything after that point.

People often talk about "the three stages of menopause", and those are the three they mean. The one that causes the symptoms is the first.

When does perimenopause start?

For most women, somewhere in the mid-forties. Some notice the first changes in their late thirties, and some sail through to their early fifties with almost nothing. The average age of menopause in Australia is about 51, and because the transition commonly runs for several years before that point, most often four to six, mid-forties is the typical starting line rather than a rule.

Age matters clinically, because the earlier symptoms start, the more a doctor wants to look properly rather than assume:

Age symptoms begin	What it is usually called	What a doctor generally does
45 and over	Perimenopause	Diagnoses on symptoms and cycle history. Hormone testing is usually not needed.
40 to 45	Possible early menopause (menopause between 40 and 45)	Takes a fuller history and often tests, to weigh other causes.
Under 40	Possible premature ovarian insufficiency	Investigates properly, usually with repeated hormone tests and specialist input.

Age bands are a guide to how doctors approach the question, not a diagnosis.

Other things move the timing. Smoking tends to bring menopause forward. Surgery to remove both ovaries brings it on immediately. Chemotherapy and radiotherapy can too. A hysterectomy that leaves the ovaries does not cause menopause, but it removes the cycle you would otherwise have used to track it, which is one reason symptoms get missed afterwards.

What are the 7 signs of perimenopause?

There is no official list of seven, but these are the seven that come up most often, in roughly the order women tend to notice them.

1. Cycle changes. Usually the first sign. Not necessarily missed periods: often a cycle that shortens by a few days, periods that get heavier or lighter, or spotting that never used to happen.
2. Broken sleep. Waking at 3am and not getting back to sleep is one of the most common early complaints, and it often appears well before any night sweats do.
3. Mood changes and new anxiety. Irritability, low mood, or a feeling of being "not yourself". Fluctuating oestrogen affects the brain chemistry that regulates mood, and this is very often put down to life stress alone.
4. Brain fog. Word-finding difficulty, losing your train of thought, walking into a room and forgetting why. Many women find this the most frightening symptom, and it is one of the most common.
5. Hot flushes and night sweats. The famous ones, and genuinely common, but frequently later arrivals rather than the opening act.
6. Joint and muscle aches. New stiffness in the mornings, sore shoulders and hips, aching hands. Under-recognised, and often blamed on exercise or age.
7. Changes in libido, skin and vaginal comfort. Lower desire, drier or more sensitive skin, and vaginal dryness that makes sex uncomfortable. These tend to build gradually rather than arrive.

The signs that often come first

Cycle changes

The very first change is usually in the length of your cycle rather than in whether you bleed at all. A cycle that runs 28 days for two decades and then starts arriving at 25, or one that suddenly stretches out, is telling you something. Later in the transition, skipped periods become the pattern.

Sleep

Waking in the small hours, sometimes with a racing mind, sometimes for no obvious reason, is a classic. Poor sleep then amplifies everything else on this list, which is part of why the whole picture can feel like burnout.

Mood, anxiety and brain fog

New or worsening anxiety in your forties, in a woman who has never been anxious, deserves a proper look rather than a shrug. So does brain fog. Both are real, both are common in the transition, and both improve for most women once the hormonal swings settle.

Palpitations, headaches and aches

Less well known, but all linked to hormonal change. New migraines, aching joints and a heart that flutters are all reasons women end up in front of a doctor without perimenopause being on the list of possibilities.

Energy, weight and libido

Persistent fatigue, weight that shifts towards the middle, and changes in libido round out the picture. For a fuller version, our perimenopause symptoms checklist groups the common symptoms so you can see how many apply to you.

What else it might be

This is the part worth taking seriously. An under-active thyroid produces fatigue, brain fog, low mood, weight change, heavier periods and feeling cold. Low iron, common when periods have become heavy, produces fatigue, brain fog, hair shedding, palpitations and breathlessness. Raised prolactin disturbs cycles. Every one of those can look like perimenopause, and every one of them is straightforward to check.

That is not a reason to doubt yourself. It is a reason to check the things that are easy to check, so that if the answer is perimenopause, it is an answer rather than an assumption.

What a blood test can and cannot show

Perimenopause is a clinical diagnosis: a doctor makes it from your age, your symptoms and your cycle history. Australasian Menopause Society guidance is clear that in women over 45 with typical symptoms, hormone tests are not needed to make it, because FSH and oestradiol swing so much during the transition that a single reading can mislead.

So why test at all? Because a well-chosen panel, read by a doctor, does three useful things:

• It rules other things in or out. Thyroid problems and low iron produce the same fatigue, fog, mood change and palpitations. Missing them means looking in the wrong place.
• It helps in the grey zones. Under 45, with atypical symptoms, after a hysterectomy, or on hormonal contraception, blood results add real information.
• It gives you a baseline. Knowing where your hormones sit now makes change over time easier to read.

Our article on the perimenopause blood test goes through exactly what each marker can and cannot tell you.

What to do if this sounds like you

Start tracking. Note your cycle length, your sleep and your symptoms for a couple of months, because a pattern on paper is far more persuasive than a memory in a ten-minute appointment. Then talk to a doctor who takes perimenopause seriously. There are effective, evidence-based options for managing symptoms, and which one suits you is a conversation with a doctor who knows your history.

If you are not sure whether what you are feeling fits, the perimenopause quiz walks through the common symptoms and points you to the right next step.

Common questions

Sources and further reading

• Australasian Menopause Society: Perimenopause or menopausal transition (information sheet)
• Australasian Menopause Society: Diagnosing menopause (information sheet)
• Jean Hailes for Women's Health: menopause
• Healthdirect: perimenopause
• Jean Hailes: let's talk about perimenopause

General information only, not medical advice. If your symptoms are severe or sudden, see a doctor promptly. This page does not replace a consultation with a doctor who knows your history; read our medical disclaimer.