Menopause is one day. Everything people describe as menopause happens either side of it. That mismatch between the word and the experience is why women spend years without a name for what is happening, and why so many are told to wait for a milestone that arrives long after the decisions that mattered.
Specialists stage the transition using STRAW+10, a set of criteria published in 2012 that defines each phase by menstrual cycle pattern rather than by symptoms or hormone values. The criteria are precise, they need no blood test, and they are more useful than any lab result for working out where you are.
The Verdict
The stages, with criteria and timelines
The table below uses the STRAW+10 framework, collapsed into the five phases that matter clinically. Note that perimenopause and postmenopause each split into two, because the physiology and the treatment questions differ meaningfully within them.
| Stage | Typical age | Duration | Defining criterion | Hormone pattern |
|---|---|---|---|---|
| Perimenopause — early transition | Usually 40s; can begin in the mid-to-late 30s | Variable, often several years | A persistent difference of 7 days or more between consecutive cycle lengths | Estradiol swings high and low; progesterone falls first as ovulatory cycles become intermittent |
| Perimenopause — late transition | Typically the 2–3 years before the final period | 1–3 years | At least one gap of 60 days or more between periods | FSH frequently above 25 IU/L on a random draw; estradiol falling but still erratic |
| Menopause | US median age 51–52; normal range roughly 45–55 | A single point, identified only in hindsight | 12 consecutive months with no period, with no other explanation | Not diagnosed by any lab value in a woman of typical age |
| Postmenopause — early | The first 5–6 years after the final period | 5–6 years | Counted from the final menstrual period | FSH continues rising then plateaus; estradiol settles low. Bone loss is fastest in this window |
| Postmenopause — late | From roughly 6 years after the final period onward | The rest of life | Continuous | Hormones stable and low. Genitourinary and skeletal changes continue and do not self-resolve |
Progesterone falls before estradiol does
Ovulation becomes intermittent well before cycles stop. Every cycle without ovulation produces no corpus luteum, and therefore little progesterone, while the follicular phase continues to generate estradiol. The result is a stretch of years with relatively unopposed estrogen.
This explains three things that women in their early 40s are frequently told are unrelated. Sleep fragments, because progesterone and its metabolite allopregnanolone have a sedative effect on the central nervous system. Anxiety appears in someone with no history of it, for the same reason. And bleeding becomes heavy, because the endometrium proliferates under estrogen without the monthly progesterone signal that would organise its shedding. All three are early-transition phenomena, and all three arrive before hot flashes.
What appears when
Symptoms follow a rough sequence. Knowing the sequence is useful for two reasons: it tells you whether what you are experiencing fits the transition, and it flags the symptoms that do not remit on their own.
| Symptom or change | When it typically appears | What is happening |
|---|---|---|
| Cycle length change | Early perimenopause | Usually the first objective sign, and the one most often dismissed as stress |
| Sleep disruption and 3am waking | Early perimenopause | Often precedes hot flashes by years; falling progesterone is a major contributor |
| New or worsening anxiety and mood lability | Early perimenopause | Estradiol volatility rather than deficiency drives this phase |
| Heavy or unpredictable bleeding | Early to late perimenopause | Unopposed estrogen in anovulatory cycles. Persistent heavy bleeding needs evaluation, not reassurance |
| Hot flashes and night sweats | Late perimenopause into early postmenopause | Peak frequency straddles the final period. Median total duration in the SWAN cohort was 7.4 years |
| Migraine change | Late perimenopause | Frequency often rises during the transition, then falls in postmenopause for many women |
| Vaginal dryness, urinary urgency, recurrent UTIs | Postmenopause, and progressive | Genitourinary syndrome of menopause. Unlike hot flashes, it does not improve with time |
| Accelerated bone loss | One year before to five years after the final period | Spine bone density can fall around 2% a year through this window |
| Rising LDL, ApoB and visceral fat | The year surrounding the final period | Occurs independently of weight change and is frequently missed |
Two entries deserve emphasis. Vasomotor symptoms are self-limiting for most women but not quickly — the median in the SWAN cohort was 7.4 years in total, and longer for women whose symptoms started early. Genitourinary syndrome of menopause runs the other way: vaginal dryness, urinary urgency and recurrent urinary tract infections are progressive and do not improve without treatment. Low-dose vaginal estrogen is effective for these, has minimal systemic absorption, and is a separate decision from systemic hormone therapy.
What each stage changes about your decisions
| Decision | Which stage it belongs to | Why the timing matters |
|---|---|---|
| Contraception | Still needed through perimenopause | Fertility is reduced, not zero. Guidance generally supports continuing contraception until 12 months of amenorrhea after 50, or 24 months if under 50 |
| Abnormal bleeding workup | Any stage | Bleeding between periods, after intercourse, or any bleeding at all after 12 months of amenorrhea requires evaluation for endometrial pathology |
| Hormone therapy timing | Best assessed in late perimenopause and early postmenopause | The risk-benefit balance is more favorable when started before age 60 or within 10 years of the final period |
| Bone density baseline | Early postmenopause, earlier with risk factors | A DEXA scan in the window of fastest loss establishes the trajectory rather than the endpoint |
| Cardiovascular baseline | Late perimenopause | ApoB and a one-time Lp(a) before the lipid shift around the final period give a usable comparison point |
| Thyroid and iron screening | Early perimenopause | Both mimic transition symptoms, both are common at this age, and both are correctable |
The hormone therapy row is the one with an expiry date. Evidence supports a more favorable risk-benefit balance for systemic therapy started before age 60 or within 10 years of the final period, compared with therapy started 15 or 20 years out into arteries that already carry established plaque. A woman deciding at 52 is deciding inside that window. The same woman deciding at 66 is deciding under a different set of trade-offs, whether or not she chose to wait. Systemic therapy has real contraindications — a history of breast cancer, unexplained vaginal bleeding, active liver disease, prior venous thromboembolism or stroke, and known coronary disease among them — and any conversation about it belongs with a clinician who knows your history.
When the timeline is not typical
Roughly 1% of women reach menopause before 40, classified as premature ovarian insufficiency, and around 5% between 40 and 45, classified as early menopause. Neither is a variant of normal to be managed with reassurance. Both carry higher long-term risks to bone density and cardiovascular health from the extended period of low estrogen, and both usually warrant hormone therapy at least until the average age of natural menopause, alongside an evaluation for causes such as autoimmune disease, fragile X premutation, or chromosomal factors.
Surgical menopause after bilateral oophorectomy is different again. The hormonal drop is immediate rather than gradual, symptoms are typically more severe, and the age at which it occurs determines much of the long-term risk picture. Chemotherapy and pelvic radiation can produce a similar abrupt transition, sometimes temporary and sometimes permanent.
See a clinician promptly for bleeding after 12 months of amenorrhea, bleeding between periods, heavy bleeding that soaks protection hourly, periods stopping before 45, or symptoms severe enough to disrupt work or sleep. None of those is something to wait out.
Frequently Asked Questions
What are the three stages of menopause?
Perimenopause is the transition, usually starting in the 40s and lasting four to ten years, when cycles change and hormones become erratic. Menopause is a single retrospective point: 12 consecutive months with no period, at a US median age of 51 to 52. Postmenopause is everything after that. Clinical staging systems subdivide these further — perimenopause into early and late transition, and postmenopause into early and late — because the physiology and the treatment decisions differ within each.
How do I know which stage I am in?
By your cycle pattern, not by a blood test. A persistent difference of seven days or more between consecutive cycle lengths marks early transition. A gap of 60 days or more between periods marks late transition. Twelve months with no period marks menopause. These criteria come from the STRAW+10 staging system, which is what specialists use, and they need no laboratory input in a woman of typical age.
How long does perimenopause last?
Four to ten years is the usual span, with the late transition accounting for the final one to three. Some women pass through in two years and some take more than a decade. Onset before 40 is classified as premature ovarian insufficiency and warrants specific evaluation rather than watchful waiting; onset between 40 and 45 is classified as early menopause and also merits a workup.
Can a blood test tell me I am in perimenopause?
Not reliably. FSH can read above 30 IU/L in one cycle and under 10 the next during the transition, and estradiol can spike above premenopausal peaks. A single draw taken during a high-estradiol cycle reads entirely normal in a woman deep into perimenopause. This is the mechanism behind being told your hormones are fine while symptoms are obvious. Labs are still worth running, for what else they find: thyroid disease, iron deficiency, and changing metabolic and cardiovascular markers.
When do hot flashes stop?
The SWAN cohort found a median total duration of vasomotor symptoms of 7.4 years, with a median of 4.5 years continuing after the final period. Women whose symptoms began in early perimenopause had the longest courses, exceeding 11 years at the median. A substantial minority have them into their 60s. Genitourinary symptoms follow a different pattern entirely — they are progressive and do not resolve with time.
Can I still get pregnant during perimenopause?
Yes. Ovulation becomes irregular rather than absent, and pregnancy remains possible until menopause is established. Standard guidance is to continue contraception until 12 months of amenorrhea if you are over 50, or 24 months if you are under 50. Irregular cycles are not a form of contraception.
What bleeding is not normal during perimenopause?
Irregular cycle length is expected. What is not expected, and needs evaluation, is bleeding between periods, bleeding after intercourse, periods lasting longer than seven days, soaking through protection hourly, passing large clots, or any bleeding at all after 12 months without a period. Postmenopausal bleeding requires assessment for endometrial cancer regardless of how light it is.
Related
- Perimenopause symptoms — the full list across nine body systems
- Perimenopause biomarker panel — what to test and when to draw it
- HRT vs BHRT — what the difference actually is
- Hormone therapy platforms compared — one rubric applied to each
- ApoB — the marker that shifts fastest across the transition
- Doctor-led options — physician-supervised platforms compared