In short
Perimenopause is recognised from your symptoms and the way your cycle changes over time, not from a single hormone blood test. Being under 45 doesn't rule it out: it's less common, but about 1 in 5 Australian women reach menopause before 45, so their perimenopause starts in their late 30s or early 40s. Sarah McLachlan, The Perimenopause Naturopath (BHSc Naturopathy)
In this post:
- How perimenopause is actually recognised
- Why a hormone blood test can't rule it in or out
- Can you be too young for perimenopause?
- What if you don't have a period to go by?
- What to track before your next appointment
- When night sweats or other changes need a GP check first
How is perimenopause diagnosed?
Perimenopause is recognised from your symptoms and how your menstrual cycle is changing, not from a scan or one blood result. In women 45 and over, clinical guidelines say new symptoms like hot flushes or night sweats plus changes to your cycle are enough to identify it, with no blood test needed [1]. Under 45, the same pattern is looked at more carefully, because other causes need ruling out. It isn't an illness to be detected. It's a phase your body is moving through, and the pattern over months tells you far more than any single day.
"The women I see usually noticed something was off long before anyone called it perimenopause. They just didn't have a name for it." ~ Sarah McLachlan, The Perimenopause Naturopath
Why can't a hormone blood test tell me if I'm in perimenopause?
Because in perimenopause your hormones swing from day to day, and sometimes hour to hour. One blood test catches one moment. Your oestradiol or FSH could look completely ordinary on Tuesday and very different by Friday, so a "normal" result doesn't mean you're not in perimenopause. That's why guidelines advise against using hormone tests to identify perimenopause in women 45 and over [1]. Blood tests still matter: they're how other causes of your symptoms, like iron, thyroid or blood sugar changes, get checked. They just can't give you a yes or no on perimenopause itself.
Can you be too young for perimenopause?
Not if your body is showing the signs. The ages you hear are averages: in Australia, perimenopause usually starts around 47 and the average age of menopause is 51 [2]. But an average is the middle, not the minimum. About 1 in 5 Australian women reach menopause before 45 [2], which means their perimenopause started earlier still, often in their late 30s or early 40s. So "you're too young" is a statement about the average woman, not about you. If you're in your late 30s or early 40s with heavier periods, worse PMS, new night sweats, broken sleep or a mood that doesn't feel like yours, perimenopause is a reasonable question to ask, alongside checking for other causes.
"I was told I was too young at 42. I believed it, pushed on for two years, and missed the window where support would have been gentle and simple." ~ Sarah McLachlan, The Perimenopause Naturopath
Too young for perimenopause?
Average is the middle, not the minimum
The ages you hear quoted are averages. Plenty of women sit either side of them.
About 1 in 5 Australian women reach menopause before 45. For them, perimenopause started earlier still, often in the late 30s or early 40s.
No period to go by? An ablation, a hormonal IUD or the pill can hide the usual clue
One hormone blood test can't rule it in or out, because hormones swing day to day
The pattern of symptoms over months is the most useful evidence
If your body is telling you something has changed, that's worth listening to, whatever your age.
Common doesn't equal normal, and young doesn't mean it can't be perimenopause.
What if you don't have a period to go by?
Then the most common clue, a changing cycle, is hidden, and you'll need to lean on your other symptoms. An endometrial ablation, a hormonal IUD or the pill can all mean you have light periods or none at all, so you can't use your cycle to track what's shifting [1]. That doesn't mean perimenopause isn't happening. It means the evidence is in your sleep, your temperature, your mood, your energy and your skin instead. Starting, stopping or changing a prescribed medication or contraceptive is always a conversation with your GP.
What should I track before my next appointment?
Track your symptoms for two to three months, because a pattern is far more persuasive than a list written the night before. Note:
- your cycle length and how heavy your periods are, if you have them
- night sweats or hot flushes, and what time they happen
- what time you wake in the night, and whether you get back to sleep
- mood, irritability and anxiety across the month
- energy, brain fog, headaches and new food reactions
Take it with you and ask directly: "Could this be perimenopause, and what else should we rule out?" If you'd like a faster starting point, the free Perimenopause Decoder quiz takes two minutes and shows which phase your symptoms fit.
When to see your GP first
Night sweats have other causes too, including infections, thyroid changes and some medications. See your GP promptly if night sweats come with unexplained weight loss, fever, a new lump, a persistent cough, or bleeding between periods or after sex. Periods that are soaking through a pad or tampon every hour or two also need a GP check. This post is general information, not a diagnosis.
Want to know if this is perimenopause?
Start with the Perimenopause Decoder. It's ten questions, about two minutes, and it'll tell you whether your symptoms fit perimenopause and which phase you're likely in, so you walk into your next appointment with more than a hunch.
Frequently asked questions
Can you be in perimenopause at 38?
Yes. It's earlier than average, but it happens. About 1 in 5 Australian women reach menopause before 45, so for them perimenopause starts in the late 30s or early 40s. If your cycle, sleep, mood or temperature has changed, it's worth asking about, and worth ruling out other causes too.
Is there a blood test for perimenopause?
Not one that can rule it in or out. Hormones swing day to day in perimenopause, so a single FSH or oestradiol result can look normal while you're well into it. Blood tests are still useful for checking iron, thyroid and blood sugar, which can cause similar symptoms.
What's the difference between perimenopause and early menopause?
Perimenopause is the transition before your final period, when hormones are fluctuating. Early menopause is when your periods stop for good between 40 and 45, and premature menopause is before 40. Perimenopause in your late 30s is not the same thing as premature menopause.
Why do I wake up drenched at 3am?
Night sweats are one of the most common perimenopause symptoms, because shifting oestrogen makes your brain's temperature control more sensitive. Blood sugar dips, alcohol and stress can make them worse. Night sweats also have other causes, so if they're new, see your GP to rule those out.
References
- National Institute for Health and Care Excellence. Menopause: identification and management (NG23), recommendations 1.3.1 to 1.3.6. Updated 2024. nice.org.uk
- Jean Hailes for Women's Health. Menopause. jeanhailes.org.au
- Healthdirect Australia. Premature and early menopause. healthdirect.gov.au
ARTICLE/CONTENT DISCLAIMER
The information provided in this blog is for personal or other non-commercial, educational purposes. It should not be considered medical or professional advice. We recommend consulting a qualified healthcare professional before taking or omitting any action based on this content. While the author uses best endeavours to provide accurate and true content, the author makes no guarantees or promises and assumes no liability regarding the accuracy, reliability or completeness of the information presented. The information, opinions, and recommendations provided are for general information only, and any reliance on this content is done at your own risk.
Any third-party materials or external content referenced in this blog do not necessarily reflect the author's opinion, standards or policies and the author assumes no liability for them.
0 Comments