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How would you actually know you're in perimenopause?

Hot flashes are the symptom everyone has heard of, and they're often not the first thing to change. I looked at which signs are well defined, which are common but poorly studied, and why there's no single test.

By Marija MarjanovićCurious, skeptical, and sharing what I find

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What happened to me

The symptom that surprised me most was my digestion. I mean serious bloating, constipation, and a general feeling of being unwell, and it never once crossed my mind that it could be connected to perimenopause. I spent years doing tests, wondering whether I had food intolerances, while my sleep problems were put down to possible anxiety or insomnia. None of the doctors I saw linked any of it to hormones, even though I was well into my forties.

In case you’re wondering whether it sorted itself out: it still comes and goes. I keep trying new things, not all of them work, and for now I’d honestly call it a work in progress.

What I wanted to know

Looking back, I’d have loved some way of telling which symptoms might belong together. So I went looking for what actually counts as a sign, which signs are well established, whether there’s a test, and why it so often takes a while for anyone, the woman herself included, to put the pieces together. The wider map is in the hormones section.

The clearest sign is your cycle

It was only when my periods started changing, in my early forties, that I began to wonder whether everything else might be hormonal too. It turns out cycle change is the one sign with a formal definition, which I found oddly reassuring.

The STRAW+10 staging system is a 2012 research consensus. It puts the start of the early transition at a persistent difference of seven days or more between the lengths of consecutive cycles, recurring within ten cycles. In practice that might look like a 26-day cycle followed by a 34-day one, happening again and again. The late transition begins when you go 60 days or more without a period, and usually lasts one to three years. Perimenopause runs from that first stage until a year after your final period. The criteria don’t work the same way after a hysterectomy or endometrial ablation, or if you have PCOS.

In SWAN, a large American study that followed women through the transition, the median age at which it began was about 47 in non-smokers and 46 in smokers. It lasted a median of roughly four and a half to eight and a half years, and tended to last longer for women who started younger. The median age at the final period was about 52 and a half. A median is only the midpoint, though, so plenty of women notice changes earlier, as I did. If you’re curious why the hormones behave this way, that’s in what actually changes in your hormones from 35.

The symptoms, and how well each is understood

Symptom How common in perimenopause How well studied
Hot flashes, night sweats 54–74%, by region Well. Large cohorts and a meta-analysis
Sleep difficulty About 45% in late perimenopause Well, as an association
Anxiety, low mood Around 30% each Moderately. Good cohorts, cause unclear
Brain fog No reliable population figure Moderately. Measurable, probably temporary
Joint and muscle pain 57–71% Moderately. Observational only
Palpitations No reliable figure Poorly. Pilot studies
Vaginal and urinary changes About 32% Moderately
Digestive symptoms No reliable figure Poorly, and the findings conflict

Hot flashes and night sweats

A 2026 review of 41 population studies, covering nearly 29,000 women, found that between 54 and 74 per cent had them, depending on region. That part I’d expected. What surprised me was how long they can go on.

Frequent hot flashes and night sweats lasted a median of 7.4 years in total, and continued for a median of 4.5 years after the final period.

Avis et al., JAMA Internal Medicine, 2015SWAN cohort · 1,449 women with frequent symptomsModerate

Sleep

This one hit close to home, given how long my own sleep problems were treated as anxiety. In a SWAN survey of more than 12,000 women aged 40 to 55, 38 per cent reported recent difficulty sleeping, and in late perimenopause that rose to about 45 per cent. Transition stage was linked to poor sleep independently of other factors, while age on its own wasn’t. Night sweats explain some of that, but apparently not all of it.

Anxiety and low mood

I’d been wondering about exactly this. A SWAN analysis followed nearly 3,000 women for ten years. Those who hadn’t been anxious at the start had higher odds of high anxiety in perimenopause or after it, even allowing for life events and hot flashes. A smaller SWAN study, at a single site, found a major depressive episode two to four times more likely during the transition than before it. A 2026 review of 102 studies puts depressive symptoms at about 32 per cent and anxiety at about 29 per cent in perimenopausal women. The anxiety figure is imprecise, though, and none of this shows that hormones cause the change.

Brain fog

I found this section strangely comforting to read. People usually get a little better at memory and processing tests when they repeat them. In SWAN, that small improvement disappeared during perimenopause and came back afterwards, which suggests the difficulty may be temporary. A 2026 review found a moderate effect compared with premenopausal women, but only in studies that staged women carefully. A research group at Weill Cornell ran a 2021 imaging study of 161 women and found that brain structure and energy use differed by stage, and largely settled after menopause. It was a single snapshot of a fairly small group, but it points the same way as SWAN.

Joint and muscle pain

Two reviews of observational studies found muscle or joint pain in 57 and 71 per cent of perimenopausal women. In the larger one, the figure for premenopausal women was about 40 per cent. The studies vary a lot and can’t show cause. Some orthopaedic specialists have proposed the term “musculoskeletal syndrome of menopause” for this cluster. I find that a useful nudge to take aches seriously. It is a proposed term rather than a diagnosis, though, and as far as I can tell the studies haven’t yet shown how much of the pain is hormonal.

Palpitations, and vaginal and urinary changes

SWAN recorded “heart pounding” as more common around the transition. The best direct study I could find, though, was a pilot of 30 women, in which palpitations were linked to hot flashes rather than to anxiety. Its authors are clear that it’s only a starting point. Vaginal and urinary symptoms affected about 32 per cent of perimenopausal women in one review, rising to 55 per cent after menopause. Unlike hot flashes, they tend not to go away on their own.

Digestion

This is where my own experience sits, and, a little frustratingly, where the evidence is thinnest.

Women in the early and late menopausal transition reported more severe bloating than earlier in life. Feelings of tension were also linked to more bloating.

Kamp et al., Journal of Women's Health, 2026Seattle Midlife Women's Health Study · 291 womenLimited

In the same women, though, reproductive hormones didn’t predict constipation or diarrhoea, while tension and the stress hormone cortisol did. A 2026 survey of Flo app users found digestive issues reported by 76 per cent of those aged 35 and over. The women chose to take part, though, and four of the authors work for or consult for Flo. The gut microbiome does look different after menopause, which offers a plausible mechanism, although that study didn’t look at symptoms or at perimenopause. As far as I can tell, the link is plausible and commonly reported, and tangled up with stress in a way nobody has unpicked yet. My own experience fits the bloating finding, but it’s still one woman’s experience, and I’d want a proper study before calling digestion a sign. Bloating also comes up in how body composition changes after 40.

What the symptom lists rest on

Doctors who have been vocal about perimenopause for years, and who see a lot of women at this stage, describe a much wider set of symptoms than hot flashes. They say it can start as early as the late thirties, and that blood tests don’t diagnose it. That broadly fits the studies above, and my own experience. The symptom percentages you’ll often see shared come from community surveys whose methods weren’t published, so I haven’t used those figures here. The experience behind them is still worth taking seriously, since clinicians often notice patterns before the research catches up. I couldn’t find trials beyond the studies above that settle the wider list. Whether that experience is enough for you, or you’d rather wait for stronger studies, is your call.

Why there’s no single test

Hormone levels swing so much during the transition that one blood sample can mislead. The UK’s NICE guideline on menopause (2015, last updated April 2026) says that in otherwise healthy women aged 45 or over, recent hot flashes plus any change in periods is enough to identify perimenopause without lab tests. It advises against using tests like AMH or estradiol to do it. An FSH test is reserved for women aged 40 to 45, to confirm menopause, or under 40. Blood tests get their own article soon.

Why it can take a while for anyone to notice

I couldn’t find a reliable figure for how long recognition takes. What exists is qualitative, and consistent. A 2025 study of women and GPs in England found women often didn’t recognise perimenopause or weren’t sure it was involved, and GPs asked about it inconsistently and acknowledged gaps in their training. A 2026 synthesis of ten studies described uncertainty on both sides and women having to advocate for themselves. Reading those, I felt a lot less alone. In a 2019 US survey of trainee doctors, only 6.8 per cent felt adequately prepared to manage menopause. I don’t read this as a story about careless doctors. These symptoms overlap with many other conditions, the research was slow to arrive, and training seems to be catching up only gradually.

When to see a doctor

If symptoms are affecting your life, that’s reason enough. See a doctor about bleeding that’s heavy or unusual for you, and about new palpitations, since heart causes need ruling out. Persistent exhaustion has other common causes, such as thyroid problems or anaemia. A ranked list of symptoms and a few months of cycle dates give you something concrete to bring. If you’re new to this site, start here; how we research explains the evidence grades.

What I still don’t know

  • Which symptoms are hormonal and which are simply midlife. Beyond cycle changes and hot flashes, nearly everything is association.
  • Whether digestion belongs on the list. I’d want a study comparing the same women before and during the transition, carefully staged.
  • How common palpitations really are. Pilot studies can’t answer that.
  • How long recognition takes. A study of primary-care records could tell us.
  • How the brain changes play out for each woman. The imaging is cross-sectional and the samples are modest.

If any of this changes, I’ll come back and update it.

Sources

  1. Harlow SD, Gass M, Hall JE, Lobo R, Maki P, Rebar RW, Sherman S, Sluss PM, de Villiers TJ; STRAW + 10 Collaborative Group. Executive summary of the Stages of Reproductive Aging Workshop + 10: addressing the unfinished agenda of staging reproductive aging Journal of Clinical Endocrinology & Metabolism. 2012. doi:10.1210/jc.2011-3362

    Consensus staging. Early transition is a persistent 7+ day difference in consecutive cycle lengths, recurring within 10 cycles. Late transition is 60+ days without a period and lasts about 1–3 years. Biomarkers are supportive only; a single FSH or estradiol sample may mislead. Criteria don't apply after hysterectomy or ablation, in PCOS or in hypothalamic amenorrhea.

  2. Paramsothy P, Harlow SD, Nan B, Greendale GA, Santoro N, Crawford SL, Gold EB, Tepper PG, Randolph JF Jr. Duration of the menopausal transition is longer in women with young age at onset: the multiethnic Study of Women's Health Across the Nation Menopause. 2017. doi:10.1097/GME.0000000000000736

    1,145 SWAN women with daily menstrual calendars. Adjusted median transition length ranged from 4.37 years (oldest onset) to 8.57 years (youngest onset). Median onset age 47.27 in non-smokers and 46.05 in smokers.

  3. Gold EB, Crawford SL, Avis NE, Crandall CJ, Matthews KA, Waetjen LE, Lee JS, Thurston R, Vuga M, Harlow SD. Factors related to age at natural menopause: longitudinal analyses from SWAN American Journal of Epidemiology. 2013. doi:10.1093/aje/kws421

    3,302 SWAN women. Median age at the natural final menstrual period was 52.54 years.

  4. National Institute for Health and Care Excellence. Menopause: identification and management (NG23) NICE guideline. 2015. Source

    UK guideline, published 12 Nov 2015, last updated 15 Apr 2026. Rec 1.3.1 says to identify perimenopause without lab tests in otherwise healthy people 45+ with recent vasomotor symptoms and any menstrual change. Rec 1.3.4 says not to use AMH, inhibin, estradiol, antral follicle count or ovarian volume at 45+. Rec 1.3.6 limits FSH to ages 40–45 (to confirm menopause) or under 40.

  5. Ellahi SA, Spector A, Talaulikar V, Faulkner A, Desai R. Global prevalence of vasomotor symptoms in the menopause transition: systematic review and meta-analysis Climacteric. 2026. doi:10.1080/13697137.2026.2722609

    41 population-based studies, 28,955 women aged 40–65. Pooled prevalence of hot flashes and night sweats ranged from 54% (Africa) to 74% (Americas and Europe), with very high heterogeneity.

  6. Avis NE, Crawford SL, Greendale G, Bromberger JT, Everson-Rose SA, Gold EB, Hess R, Joffe H, Kravitz HM, Tepper PG, Thurston RC; SWAN. Duration of menopausal vasomotor symptoms over the menopause transition JAMA Internal Medicine. 2015. doi:10.1001/jamainternmed.2014.8063

    1,449 SWAN women with frequent hot flashes or night sweats. Median total duration 7.4 years, and a median 4.5 years after the final period. Women whose symptoms began before or early in the transition had a median of more than 11.8 years.

  7. Santoro N. Perimenopause: From Research to Practice Journal of Women's Health. 2016. doi:10.1089/jwh.2015.5556

    Narrative review. About a third of women find hot flashes moderate to severe. Vaginal dryness and painful sex affect about a third in later stages and, unlike hot flashes, don't resolve without treatment.

  8. Kravitz HM, Ganz PA, Bromberger J, Powell LH, Sutton-Tyrrell K, Meyer PM. Sleep difficulty in women at midlife: a community survey of sleep and the menopausal transition Menopause. 2003. doi:10.1097/00042192-200310010-00005

    SWAN survey of 12,603 women aged 40–55. 38% reported difficulty sleeping in the past two weeks, rising to 45.4% in late perimenopause. Transition stage was associated with sleep difficulty independently of other factors; age alone was not.

  9. Bromberger JT, Kravitz HM, Chang Y, Randolph JF Jr, Avis NE, Gold EB, Matthews KA. Does risk for anxiety increase during the menopausal transition? Study of women's health across the nation Menopause. 2013. doi:10.1097/GME.0b013e3182730599

    2,956 SWAN women followed for 10 years. Women with low anxiety at the start had higher odds of high anxiety in perimenopause or postmenopause (OR 1.56–1.61), independent of life events and hot flashes. Women already highly anxious didn't change by stage.

  10. Bromberger JT, Kravitz HM, Chang YF, Cyranowski JM, Brown C, Matthews KA. Major depression during and after the menopausal transition: Study of Women's Health Across the Nation (SWAN) Psychological Medicine. 2011. doi:10.1017/S003329171100016X

    221 women at one SWAN site, interviewed yearly. A major depressive episode was 2–4 times more likely in perimenopause or early postmenopause than in premenopause, independent of depression history and hot flashes.

  11. Balasubramanian I, Abhijita B, Krishnamoorthy Y, Gnanadhas J, Beg MJ, Menon V. Prevalence and incidence of depressive, anxiety, and insomnia symptoms in perimenopausal and postmenopausal women: Systematic review and meta-analysis General Hospital Psychiatry. 2026. doi:10.1016/j.genhosppsych.2026.03.010

    102 observational studies. In perimenopausal women, point prevalence was 32% for depressive symptoms, 29% for anxiety (95% CI 15–45) and 27% for insomnia. No premenopausal comparison in the abstract.

  12. Greendale GA, Huang MH, Wight RG, Seeman T, Luetters C, Avis NE, Johnston J, Karlamangla AS. Effects of the menopause transition and hormone use on cognitive performance in midlife women Neurology. 2009. doi:10.1212/WNL.0b013e3181a71193

    2,362 SWAN women followed for four years. The usual improvement with repeated testing in processing speed and verbal memory was absent in perimenopause and returned in postmenopause.

  13. Bangle A, Williams D, Walters J, Nguyen L. Cognitive functioning in perimenopause: An updated systematic review and meta-analysis Psychology and Aging. 2026. doi:10.1037/pag0000946

    26 studies, 9,428 participants. Perimenopausal women did worse than premenopausal women (moderate effect), but only in studies using STRAW+10 staging. Self-reported cognition trended worse than objective performance.

  14. Mosconi L, Berti V, Dyke J, et al. (Brinton RD senior author). Menopause impacts human brain structure, connectivity, energy metabolism, and amyloid-beta deposition Scientific Reports. 2021. doi:10.1038/s41598-021-90084-y

    Cross-sectional brain imaging in 161 women aged 40–65 (30 pre, 57 peri, 74 post). Brain structure, connectivity and energy metabolism differed by stage, and largely stabilised after menopause.

  15. Kruse C, McKechnie T, Dworsky-Fried J, Sardar A, Hacker G, Rattansi S, Fang E, Sprague S, Shea AK, Bhandari M. Musculoskeletal Manifestations of Perimenopause: A Systematic Review and Meta-Analysis of 93,021 Women JB JS Open Access. 2026. doi:10.2106/JBJS.OA.25.00254

    37 observational studies, 93,021 women. Muscle or joint pain in 40% of premenopausal, 57% of perimenopausal and 59% of postmenopausal women. Very high heterogeneity. One author declares honoraria from pharmaceutical companies.

  16. Lu CB, Liu PF, Zhou YS, Meng FC, Qiao TY, Yang XJ, Li XY, Xue Q, Xu H, Liu Y, Han Y, Zhang Y. Musculoskeletal Pain during the Menopausal Transition: A Systematic Review and Meta-Analysis Neural Plasticity. 2020. doi:10.1155/2020/8842110

    16 studies. Musculoskeletal pain in an estimated 71% of perimenopausal women, with higher odds than in premenopausal women (OR 1.63).

  17. Wright VJ, Schwartzman JD, Itinoche R, Wittstein J. The musculoskeletal syndrome of menopause Climacteric. 2024. doi:10.1080/13697137.2024.2380363

    Narrative review by orthopaedic specialists proposing an umbrella term for joint pain, muscle loss, bone loss and osteoarthritis progression around menopause. Cited for the proposed term only; its prevalence figures are not used here because their source couldn't be traced.

  18. Gold EB, Sternfeld B, Kelsey JL, Brown C, Mouton C, Reame N, Salamone L, Stellato R. Relation of demographic and lifestyle factors to symptoms in a multi-racial/ethnic population of women 40-55 years of age American Journal of Epidemiology. 2000. doi:10.1093/aje/152.5.463

    SWAN survey of 16,065 women aged 40–55. Being peri- or postmenopausal gave the highest odds for all symptoms measured, including heart pounding, forgetfulness, stiffness and soreness. Reporting varied by ethnicity and circumstances.

  19. Carpenter JS, Jaynes HA, Alzahrani MA, Chen PS, Kovacs RJ, Tisdale JE. Palpitations in midlife women: the Menopause Racing Heart Pilot Study Menopause. 2025. doi:10.1097/GME.0000000000002538

    Pilot study, 15 women with and 15 without palpitations, aged 46–62, with up to four weeks of heart monitoring. Palpitations were linked to hot flashes and diabetes rather than anxiety. Explicitly hypothesis-generating.

  20. Nik Hazlina NH, Norhayati MN, Shaiful Bahari I, Nik Muhammad Arif NA. Prevalence of Psychosomatic and Genitourinary Syndrome Among Menopausal Women: A Systematic Review and Meta-Analysis Frontiers in Medicine. 2022. doi:10.3389/fmed.2022.848202

    29 studies. Genitourinary symptoms in 19.2% of premenopausal, 31.9% of perimenopausal and 55.1% of postmenopausal women.

  21. Kamp KJ, Callan NGL, Mitchell ES, Heitkemper MM, Woods NF. Bloating During the Menopause Transition: Observations from the Seattle Midlife Women's Health Study Journal of Women's Health. 2026. doi:10.1177/15409996261455326

    291 women keeping health diaries. Early and late transition stages were associated with more severe bloating; so was tension.

  22. Callan NGL, Mitchell ES, Heitkemper MM, Woods NF. Constipation and diarrhea during the menopause transition and early postmenopause: observations from the Seattle Midlife Women's Health Study Menopause. 2018. doi:10.1097/GME.0000000000001057

    Same 291-woman cohort. Reproductive hormones did not predict constipation or diarrhoea severity; tension and cortisol (constipation) and tension and age (diarrhoea) did.

  23. Hedges MS, Hewings-Martin Y, Karam J, Castaneda R, Cunningham AC, Xu Y, Zhaunova L, Faubion SS, Shufelt CL. Global perspectives on perimenopause: a digital survey of knowledge and symptoms using the Flo application Menopause. 2026. doi:10.1097/GME.0000000000002730

    17,494 users of the Flo app. Hot flashes were the most recognised symptom (71%). Among the 12,681 aged 35+, fatigue (83%), irritability (80%) and digestive issues (76%) were among the most reported. Self-selected app users; four authors are Flo Health employees or consultants with equity.

  24. Peters BA, Lin J, Qi Q, Usyk M, Isasi CR, Mossavar-Rahmani Y, Derby CA, Santoro N, Perreira KM, Daviglus ML, Kominiarek MA, Cai J, Knight R, Burk RD, Kaplan RC. Menopause Is Associated with an Altered Gut Microbiome and Estrobolome, with Implications for Adverse Cardiometabolic Risk in the Hispanic Community Health Study/Study of Latinos mSystems. 2022. doi:10.1128/msystems.00273-22

    Stool analysis in 2,300 people. Postmenopausal women's gut microbiome differed from premenopausal women's. Cross-sectional; it did not study digestive symptoms or perimenopause. Mechanism only.

  25. Burgin J, Pyne Y, Davies A, Kessler D. Mental health consultations during the perimenopausal age range: a qualitative study of GP and patient experiences British Journal of General Practice. 2025. doi:10.3399/BJGP.2025.0069

    Interviews with 18 women aged 45–55 and 11 GPs in south-west England. Women often didn't recognise perimenopause or weren't sure it was involved; GPs asked about it inconsistently and acknowledged training gaps.

  26. McCarthy LJ, O'Mahony A, Jennings AA, McHugh S. Navigating Uncharted Waters: A Meta-Ethnography Exploring General Practitioners and Women's Experience of Perimenopause Consultations in General Practice International Journal of Women's Health. 2026. doi:10.2147/IJWH.S585874

    Synthesis of 10 qualitative studies. Themes were uncertainty, women having to advocate for themselves, and fragmented care.

  27. Kling JM, MacLaughlin KL, Schnatz PF, Crandall CJ, Skinner LJ, Stuenkel CA, Kaunitz AM, Bitner DL, Mara K, Fohmader Hilsaca KS, Faubion SS. Menopause Management Knowledge in Postgraduate Family Medicine, Internal Medicine, and Obstetrics and Gynecology Residents: A Cross-Sectional Survey Mayo Clinic Proceedings. 2019. doi:10.1016/j.mayocp.2018.08.033

    183 US trainee doctors (26% response). 20.3% had had no menopause lectures, and 6.8% felt adequately prepared to manage menopausal women.