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Perimenopause: what happens in your body and what helps

Your cycle suddenly runs shorter, or skips a month entirely. Nights when you are wide awake at four in the morning.

Medically reviewed by Dr. William Declerck, physician

Reviewed on . 13-minute read.

What is perimenopause?

Perimenopause is the transition phase before menopause. Your ovaries gradually wind down their work, so your hormone levels start to fluctuate and your cycle changes. The phase begins with the first hormone-related symptoms, cycle irregularities among them, and ends one year after your last period.1

In everyday English this is often just called "the change" or "the menopause transition". Peri comes from the Greek for "around": perimenopause is literally the period around your menopause. It is the phase where most symptoms show up, often while you are still having periods. That is exactly why many women, and many doctors, make the link to hormones so late.

You will also come across the word premenopause. Strictly speaking it means something different: the entire fertile period before menopause, including the years with no symptoms at all. In practice most people use premenopause and perimenopause interchangeably for the same phase, the years of fluctuating hormones before your last period. If you searched for premenopause, this page is about that same phase.

The four stages in order:

  1. Premenopause: strictly your whole fertile life before menopause, in everyday use often a synonym for perimenopause.
  2. Perimenopause: the phase that starts with the first hormone-related symptoms, cycle irregularities among them, and runs until one year after your last period.
  3. Menopause: strictly your very last period. You only know for sure a year later, once twelve months have passed without one. That last period falls on average around age 51.2,3
  4. Postmenopause: the whole period after that.
Timeline of the four stages of the menopause transition: premenopause, perimenopause, menopause and postmenopause. Menopause is a single moment, the last period, around age 51 on average, confirmed after 12 months without a period; perimenopause runs until one year after that last period.
The four stages of the transition. Perimenopause only ends one year after your last period.

What the figure shows

  • Premenopause: your fertile years before menopause.
  • Perimenopause: starts with the first hormone-related symptoms and runs until one year after your last period.
  • Menopause: a single moment, your last period, on average around age 51, confirmed after 12 months without a period.
  • Postmenopause: the whole period after that.

At what age does perimenopause start?

Perimenopause usually starts somewhere in your forties, on average four to six years before your last period.4 In some women the first signals appear around 38, in others not until close to 48. Your last period, menopause itself, falls on average around age 51; you only know for sure a year later.2,4

The first phase is often subtle. Your cycle gets a few days shorter or more erratic, you sleep more lightly, you recover more slowly from busy weeks. Because you are still having full periods at that point, you are more likely to blame stress or having too much on your plate than your hormones.

When your perimenopause starts is partly down to heredity: the age at which your mother reached menopause gives an indication. Smoking brings menopause forward.4

If your periods stop completely before you turn 40, doctors call this premature ovarian insufficiency (POI). It affects roughly one in a hundred women and always needs medical follow-up.2,5 In that case, do not wait and see. Make an appointment with your GP or gynaecologist.

How do you know if you are in perimenopause?

A changing cycle is one of the most distinctive signals of perimenopause: shorter, longer, more unpredictable or heavier than before. Together with typical symptoms such as hot flushes, it points strongly in that direction. But by no means every woman gets those classic symptoms, and their absence certainly does not rule perimenopause out. That is exactly what makes it so hard to recognise at times.

No single test gives you a definite answer in one moment. Precisely because your hormones fluctuate so much in this phase, one measurement says little.4 The pattern over several months tells you far more. So keep track of your cycle and your symptoms for two to three months, on paper or in an app. That overview also puts you in a stronger position in the consulting room.

Schematic chart of oestrogen and progesterone: stable in the fertile years, fluctuating strongly in perimenopause, low after menopause. Two blood tests in perimenopause give different results.
A schematic view of your hormone levels around the transition. Not measured values: it is the pattern that matters, not the numbers.

What the figure shows

  • Fertile years: oestrogen and progesterone are stable.
  • Perimenopause: both hormones fluctuate strongly.
  • After menopause: both hormones stay low.
  • Two blood tests in perimenopause give different results.

Want a first indication now? Do the symptom check: a short questionnaire that gives a clear overview of the symptoms that can be linked to perimenopause and menopause. You can take the result to your care provider.

One trap: if you take the pill, use a hormonal coil or no longer have a womb, you often cannot see the changes in your cycle.4,5,6 Your periods stay artificially regular or disappear entirely, while your body is already in perimenopause. In that case your other symptoms are your most important clue.

Perimenopause symptoms

Check for yourself

Which symptoms do you recognise?

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Perimenopause symptoms rarely come alone. Oestrogen and progesterone act on almost every system in your body, directly or indirectly, from your brain to your joints, so the symptoms can turn up anywhere. Around eight in ten women get hot flushes or night sweats during the transition, and it usually does not stop there.3,4

The best known are the heat symptoms. Night sweats and hot flushes catch you at the strangest moments, and many women are also startled by sudden heart palpitations that seem to come from nowhere.

Just as disruptive is what happens at night. Sleep problems are among the most reported symptoms in this phase: trouble falling asleep, lying wide awake at four in the morning, or waking as if you never slept. In the daytime that shows up as a fatigue that a weekend of rest does not shift.

Your head is in it too. Mood swings can leave you not recognising yourself, and anxious feelings surface in women who never had them before. Many women also describe brain fog: slower thinking, losing words, struggling to focus. Headache or migraine can get worse in this phase as your hormones swing more sharply.3

Your body changes along with it. Weight gain, especially around the belly, and a bloated feeling are common complaints. The same goes for muscle pain and joint complaints, which are often wrongly put down to age. Less visible but important: bone breakdown speeds up in this phase. As a result your bone density falls faster and your risk of fractures rises.3 Your skin and hair feel the hormonal shift too: hair loss and acne regularly come back in perimenopause.

And then there is what you might be slowest to bring up. Vaginal dryness makes sex uncomfortable or painful, and many women notice their libido changing. Both are very treatable, and neither is something you simply have to put up with.

Recognise several of these symptoms? Each one has its own page with an explanation of the cause, how long it lasts and what helps. If you would like a clear overview of them first, the symptom check gives you one.

How long does perimenopause last?

Perimenopause lasts four to six years on average, although some women reach menopause after only a few months of irregular cycles.4 Hot flushes and night sweats last more than seven years on average, counted across the whole transition.6,7

Those figures sound discouraging, so two things to hold on to. First, the phase comes in waves: months with heavy symptoms alternate with calmer stretches. Second, you do not have to wait for it to pass. For most symptoms there is an approach that works, from lifestyle to medication. How you get through those years is partly in your own hands.

Diagnosis: can you test for perimenopause?

There is no single reliable perimenopause test. If you are over 45 and have typical symptoms along with a changing cycle, a doctor makes the diagnosis based on your story, without a blood test. That is what the Belgian and the international guidelines say.2,5,6

That surprises many women. A hormone test sounds logical, but in perimenopause your hormone levels jump up and down from week to week. An FSH level that is raised today can be back to normal next month.4 So one blood draw tells you little, and a normal result does not rule perimenopause out. The same goes for self-tests from the pharmacy or online: they give a snapshot of values that fluctuate constantly, and therefore often give a falsely reassuring or falsely alarming result.

In a few situations a blood test is worthwhile. If you are between 40 and 45 and the picture is unclear, a doctor may consider an FSH measurement. If you are younger than 40, further investigation always follows.2,5 And separately from your hormones, a blood test can rule out other explanations that look like perimenopause symptoms, such as an underactive thyroid or anaemia from heavy bleeding.2,4

Check for yourself

Is a blood test worthwhile for you?

Choose your age.

Separately from your hormones, a blood test can rule out other explanations that look like perimenopause symptoms, such as an underactive thyroid or anaemia from heavy bleeding.

What can help during perimenopause?

  1. Lifestyle and nutrition

    Around 150 minutes of moderate activity a week, topped up with strength training.

    Read moreabout lifestyle and nutrition
  2. Hormone therapy

    The most effective treatment for hot flushes and night sweats.

    Read moreabout hormone therapy
  3. Other medication and support

    Non-hormonal medicines that reduce hot flushes.

    Read moreabout other medication and support

There is more you can do than grit your teeth. The treatment with the strongest evidence against hot flushes and night sweats is hormone therapy, and alongside it, lifestyle, nutrition and non-hormonal options make a real difference for many women.2,5,6,8 What makes sense for you depends on your symptoms, your health and your preference.

Lifestyle and nutrition

Movement is the best all-rounder. Aim for around 150 minutes of moderate activity a week, topped up with strength training to support your muscles and bones.3 Keep an eye on getting enough calcium and vitamin D for your bones too.2 Cutting back on alcohol and stopping smoking are basic advice in the guidelines: they lower your risk of cardiovascular disease, osteoporosis and certain cancers.2,6 Do alcohol or caffeine set off your hot flushes? Then cutting back is worth trying for that too.

Supplements can be a valuable addition, for instance where there is a specific deficiency or an increased need. At the same time, the evidence for some popular supplements is still limited or mixed, and quality can vary a lot between products and brands.2,5 Certain herbal preparations can also interact with medication, so if in doubt, discuss them with your doctor or pharmacist.5 See supplements above all as an addition to a solid base: healthy, varied food, enough movement and a good night's sleep.

Hormone therapy

Hormone therapy tops up the falling oestrogen and is the most effective treatment for hot flushes and night sweats. Women who sleep better often feel their mood and concentration lift too. For most healthy women with troublesome symptoms, the benefits outweigh the risks when treatment is started around the time of the transition.6,8

In perimenopause there is a specific consideration on top: you still have your own cycle, your hormones can swing hard and you can still get pregnant. The form and dose are matched to that, and contraception stays a separate point to think about.3,5 That is exactly why this is something to look at together with a care provider, based on your situation.

Other medication and support

If you are looking for an alternative to hormones, you are not out of options. There are non-hormonal medicines that reduce hot flushes, and cognitive behavioural therapy demonstrably helps with the burden of hot flushes, sleep problems and low mood.5,6 For vaginal dryness there are local treatments that have little to no effect on the rest of your body.5,8

When should you talk to a care provider?

You do not have to wait until the symptoms turn your daily life upside down. If your symptoms weigh on your work, your relationship or your mood, or if you are unsure about hormone therapy, that is reason enough for a conversation with someone who knows perimenopause inside out.

In Belgium your usual path starts with the GP, who can rule out other causes and refer you to a gynaecologist if needed. Some hospitals have a separate menopause clinic. Good care exists, then, even if the wait is sometimes long and the consultation time short.

Want to speak straight away to someone who works on the menopause transition day in, day out? On Uma you will find care providers who specialise in (peri)menopause. Your consultation takes place online, you discuss all your symptoms together, including the ones you had not yet connected, and you leave with a concrete plan.

One important exception to "you can safely wait and see": do go to a doctor straight away for very heavy bleeding, bleeding after sex, or bleeding that returns after you have gone twelve months without a period.4 Usually the explanation is harmless, but this is something a doctor should check.

Sources (8)

  1. Harlow, S.D. et al. (2012). Executive summary of the Stages of Reproductive Aging Workshop + 10 (STRAW+10). Menopause, 19(4), 387–395. https://pmc.ncbi.nlm.nih.gov/articles/PMC3340904/
  2. RIZIV/INAMI (2024). Consensus conference: The management of menopause. https://www.riziv.fgov.be/SiteCollectionDocuments/consensus_lange_tekst_20240530.pdf
  3. Panay, N. et al. (2025). International Menopause Society (IMS) recommendations and key messages on women's midlife health and menopause. Climacteric, 28(6), 634–656. https://doi.org/10.1080/13697137.2025.2585487
  4. Nederlands Huisartsen Genootschap (2022). NHG-Standaard De overgang (M73), versie 3.0. (Dutch GP guideline, NL only.) https://richtlijnen.nhg.org/standaarden/de-overgang
  5. National Institute for Health and Care Excellence (2024). Menopause: identification and management. NICE Guideline NG23. https://www.nice.org.uk/guidance/ng23
  6. Rozenberg, S. et al. (2026). Guidelines Menopause. Belgian Menopause Society. https://www.menopausesociety.be/nieuwsbericht/guidelines-menopause-bms/
  7. Avis, N.E. et al. (2015). Duration of menopausal vasomotor symptoms over the menopause transition (SWAN). JAMA Internal Medicine, 175(4), 531–539. https://pmc.ncbi.nlm.nih.gov/articles/PMC4433164/
  8. BCFI/CBIP (2025). Hormone therapy during perimenopause: benefits and drawbacks. (Belgian source, NL page.) https://www.bcfi.be/nl/hormoontherapie-tijdens-de-perimenopauze-voor-en-nadelen/

The content on this page is intended for informational purposes and does not replace medical advice. Please consult a physician for a personal assessment.

Frequently asked questions about perimenopause

Perimenopause is diagnosed based on the full clinical picture, not a single test. A useful starting point is mapping the broad spectrum of possible symptoms, which you can do with the symptom check.

A care provider then looks at typical signals such as hot flushes and changes to your menstrual cycle, and rules out other possible causes. Because no blood test can confirm or exclude perimenopause with certainty, the overall pattern of symptoms matters most.

Sometimes the response to treatment adds clarity too: if your symptoms improve clearly with an appropriate treatment, that supports the diagnosis.

Yes. A changing cycle is a common signal of perimenopause, but not every woman notices it. If you take the pill or have a hormonal coil, you will not see cycle changes at all.

In those cases, other symptoms become the most important indicator: poorer sleep, hot flushes, mood swings, or joint pain. A care provider looks at the whole picture, not only at your cycle.

The first signs of perimenopause are often subtle. Common early signals include:

  • A menstrual cycle that shifts by a few days
  • Lighter or heavier bleeding than usual
  • Sleeping more shallowly
  • Being quicker to snap and slower to recover from a busy period

Hot flushes and night sweats tend to appear later. If you recognise this pattern, tracking your cycle and symptoms for a few months can give a care provider useful information.

Perimenopause lasts four to six years on average, though for some women it is over within a few months. The phase officially ends one year after your last period. Symptoms can continue for some time after that point, and for most women there are treatment options that can help.

A blood test cannot reliably confirm or rule out perimenopause. Hormone levels fluctuate so strongly during this phase that a single measurement says little: a normal result does not mean perimenopause is not the cause.

  • Over 45: a doctor will generally make the diagnosis based on your symptoms and cycle, without relying on blood tests.
  • Under 45, and especially under 40: a blood test is worthwhile to rule out early menopause or premature ovarian insufficiency (POI), which require different management.

Yes. As long as you ovulate occasionally, pregnancy is possible, even with an irregular cycle. The general guidance is:

  • Use contraception until one year after your last period, if that falls after age 50
  • Use contraception until two years after your last period, if you are younger than 50

If you use hormonal contraception, different considerations apply. Talk to your doctor about which form is appropriate during this phase.

For most healthy women with troublesome symptoms, the benefits of hormone therapy outweigh the risks when treatment is started around the time of the transition. The risk profile varies depending on the type of hormone therapy and how it is taken, and certain conditions in your medical history may require extra caution. There is no single answer that applies to everyone. A care provider weighs this up with you, based on your symptoms, history, and preferences.

Does this sound familiar?

Talk it through with a care provider on Uma who works with (peri)menopause every day. You leave with a clear explanation and concrete next steps. No account needed · booking takes under 2 minutes.