Perimenopause: How Do You Actually Know If You're In It?
Are you in perimenopause? How can you tell? And do you need a blood test to find out?
These are questions I hear regularly as a GP, and I can understand why women are confused. We're talking about perimenopause more than ever, which is a good thing, but there's also an awful lot of conflicting information.
Some women are convinced they're perimenopausal but have been told their hormone levels are normal. Others have symptoms they think might be related to menopause but aren't sure.
So how do we actually work it out?
Watch my video below, where I talk through how we assess perimenopause, when blood tests help and why the answer isn't always straightforward.
What is perimenopause?
Perimenopause is the transitional period leading up to menopause, when hormone levels fluctuate and menstrual cycles and symptoms may begin to change.
Menopause itself is defined retrospectively, once you've gone 12 consecutive months without a period, provided you're not using hormonal contraception or another treatment that affects your bleeding.
The average age of menopause in the UK is around 51, but perimenopause can begin several years earlier.
How do you know if you're in perimenopause?
For most otherwise healthy women aged 45 and over, we can identify perimenopause from their symptoms and menstrual history, without needing routine hormone blood tests.
We consider several things together:
Your age: Perimenopause becomes increasingly likely as you approach the typical age of menopause.
Your periods: Changes in cycle length, regularity or bleeding patterns can be important clues.
Your symptoms: Hot flushes, night sweats, sleep disturbance, mood changes and vaginal dryness are among the possible symptoms.
Your medical history: Other health conditions, medications and hormonal contraception can affect the picture.
There's no single symptom that proves you're perimenopausal. And not every symptom that appears in your 40s is necessarily caused by changing hormones.
Can a blood test diagnose perimenopause?
This is probably one of the biggest areas of confusion.
Hormones such as follicle-stimulating hormone (FSH) and oestradiol can fluctuate considerably during perimenopause.
That means a blood test might show hormone levels within the expected range on one day, even though you're experiencing perimenopausal changes.
A normal hormone blood test does not rule out perimenopause.
For women aged 45 and over with typical symptoms, NICE guidance recommends identifying perimenopause clinically rather than routinely testing hormone levels.
But that doesn't mean blood tests are never useful.
When might blood tests be helpful?
If you're aged 40 to 45 and experiencing symptoms suggestive of menopause, an FSH test may sometimes help with the assessment.
If you're under 40 and menopause is suspected, further investigation is particularly important because we need to consider premature ovarian insufficiency.
Blood tests may also be appropriate when we're investigating other possible causes of symptoms, such as thyroid problems or anaemia.
The important thing is choosing tests that will genuinely help answer a clinical question, rather than ordering a long list of hormones that may create more confusion.
What if you're taking hormonal contraception?
This can make things more complicated.
Some hormonal contraceptives change or stop your periods, which means your bleeding pattern may no longer be a reliable guide.
Combined hormonal contraception also affects hormone measurements, making FSH testing unreliable for determining menopausal status while you're using it.
The best approach depends on your age, the contraception you're using and your individual circumstances.
And remember, being perimenopausal doesn't necessarily mean you can no longer become pregnant.
Could your symptoms be something else?
Absolutely, and this is something I think is really important.
Just because you're in your 40s or 50s doesn't mean every new symptom should automatically be attributed to menopause.
Fatigue, poor sleep, mood changes and brain fog can have several possible explanations.
Similarly, unusual bleeding, particularly bleeding between periods, after sex or after menopause, deserves proper assessment rather than being dismissed as hormonal.
Not needing a hormone blood test is not the same as not needing a proper clinical assessment.
So what's the best way to find out?
If you're wondering whether you're in perimenopause, start by looking at the whole picture rather than focusing on a single hormone result.
Think about your age, whether your periods have changed, what symptoms you're experiencing and how they're affecting your life.
If you're unsure, your symptoms are troublesome, or something doesn't seem right, speak to your GP.
You don't need to arrive with a diagnosis, and you certainly don't need to pay for an expensive private hormone panel before asking for help.
A question for you
This article is part of my new Dr Sophie GP series, where I'm answering the questions women actually want to ask about their health.
What would you like me to cover next?
Leave a comment on the YouTube video. I'm using your questions to help shape future episodes.
Dr Sophie Newton is a practising NHS GP and health educator. This article provides general information and isn't a substitute for individual medical advice.
Further reading: NICE guideline NG23: Menopause, identification and management