Perimenopause Periods: Heavier, Closer, Longer: What Is Normal and What Needs Checking

Key Takeaways
- Persistent variation of seven days or more in cycle length is the clinical marker of the early menopause transition, and a gap of 60 days or more marks the late transition.
- Two periods in one calendar month at 45 is most often a cycle that has shortened to 21–24 days because rising FSH speeds up the first half of the cycle.
- Heavy bleeding is defined by soaking protection every one to two hours, clots larger than a quarter (about 2.5 cm), changing overnight or bleeding beyond seven days, whatever your age.
- In a large US cohort, most women had at least one bleed lasting ten days or more during perimenopause and roughly a third had three or more, so a single long bleed is expected while a repeating pattern is checked.
- Any bleeding after 12 consecutive period-free months is evaluated promptly, because around nine in ten endometrial cancers present with bleeding, even though most postmenopausal bleeding has a benign cause.
- Contraception is advised until 12 months after the last period, or two years after it if you are under 50, because ovulation becomes unpredictable before it stops.
Perimenopause periods commonly become irregular in the years before menopause: cycles may shorten to 21–24 days, then lengthen, and flow can be heavier or lighter than before. Those shifts are usually hormonal. Bleeding that soaks a pad or tampon hourly for two hours or more, lasts beyond seven days, happens after sex, or returns after 12 period-free months should be checked by a clinician.
A reader wrote to us last month with a photo of her period-tracking app. Forty-six years old, two red blocks in a single month, the second one heavy enough that she had canceled a work trip. Underneath, she had typed one line: is this the perimenopause everyone is posting about, or is this something else?
It is a fair question, and a timely one. As of September 2026, short videos claiming that two periods a month ‘confirms’ perimenopause, or that heavy bleeding in your 40s is simply something to wait out, are circulating widely, and searches for perimenopause periods have climbed with them. Some of what is being shared is accurate. Some of it quietly skips the part where certain bleeding patterns deserve an examination.
This piece sets out what the cycle actually does during the transition, which changes are expected, which ones are not, and how strong the evidence is behind each statement. Think of it as the explanation your calendar app cannot give you.
Why do perimenopause periods change in the first place?
Perimenopause is the transition toward menopause, the stretch of years when the ovaries wind down, and menopause itself is defined by 12 consecutive months without a period. The average age at menopause in the United States is 51. The transition usually begins in the mid-40s, although it can start in the late 30s, and Mayo Clinic puts the typical length at about four years; for some women it runs eight to ten.
The engine behind the bleeding changes is ovulation, or rather its growing unreliability. In a regular cycle an egg is released around mid-cycle, and the leftover follicle produces progesterone, a hormone that stabilizes the uterine lining (the endometrium) and triggers a predictable shed when levels fall. As the egg supply dwindles, the brain pushes harder with follicle-stimulating hormone (FSH), the signal that recruits eggs. Early on, that extra push can make follicles mature faster, which is why many women notice cycles shortening before anything else.
Later, some cycles pass with no ovulation at all. Estrogen may still be produced, sometimes in erratic surges, but without progesterone the lining keeps building rather than shedding on schedule. When it finally comes away it can be thick, heavy and clotted, or it may slough unevenly as spotting. Picture a lawn that gets watered and fertilized but never mown: eventually it comes down all at once.
Three patterns therefore tend to appear in sequence, with plenty of overlap: shorter cycles, then unpredictable ones with occasional heavy or prolonged bleeds, then longer gaps that stretch toward the final period. The swings themselves are the signature. A hormone test on any single day captures one frame of a fast-moving film, which is why clinicians usually diagnose perimenopause from the pattern of cycles and symptoms rather than a lab value.
What does a perimenopausal period actually look like?
Ask ten women and you will get ten different descriptions, which is itself the honest answer. Still, a few features recur often enough to be worth naming.

Timing drifts first. A cycle that ran 28 days for two decades starts arriving at 24 or 25, or it stays at 28 one month and jumps to 35 the next. Researchers who staged the transition for large studies use a simple threshold: once the length between periods varies by seven days or more on a persistent basis, you are considered to be in the early transition. That is a clinical rule, not a diagnosis you need to make at home, but it explains why a week of wobble counts.
Flow changes next, and in both directions. Some months are lighter and shorter, almost an afterthought. Others open with a day or two of brown spotting, build to a heavy, clot-laden middle, and trail off over a week. Clots are simply blood that pooled in the uterus long enough to set; occasional small ones are expected, while repeated clots larger than a quarter (about 2.5 cm) are one of the markers the NHS uses for heavy bleeding.
Symptoms around the bleed can intensify. Breast tenderness, bloating, sleep disruption and mood shifts in the days before a period often feel sharper, because estrogen swings are wider than they used to be. Hot flashes may cluster around the bleed as well.
What a perimenopausal period does not look like is a steady decline. The idea that flow gently tapers for a few years and then stops is true for some women and false for many others. If your experience feels chaotic rather than gradual, that does not by itself signal a problem; it signals a transition doing what transitions do.
Why am I having two periods a month at 45?
Two bleeds in one calendar month is one of the most searched questions about perimenopause periods, and the most common explanation is arithmetic plus hormones. If your cycle has shortened to 21 or 22 days, a period that starts on the first of the month will be followed by another before the month ends. Nothing has doubled; the interval has shrunk.
The shrinkage has a mechanism. Rising FSH in the early transition shortens the first half of the cycle, the follicular phase, because follicles are recruited and matured more quickly. The second half, driven by progesterone after ovulation, stays roughly the same length. The net effect is a cycle that lands several days early, month after month, until the pattern breaks up into something less regular.
A second explanation is that one of the two bleeds is not a true period. A cycle without ovulation can produce a withdrawal bleed when estrogen dips, and that bleed can look and feel like a light period. Mid-cycle spotting at the time of ovulation, which some women notice for the first time in their 40s, is another candidate.
The third possibility is the one that deserves a check: bleeding between periods caused by something structural, such as a polyp or fibroid, or by a thickened lining. The distinction matters because the first two explanations are self-limiting and the third usually benefits from an examination.
A practical way to sort them is to log the dates and heaviness for two or three cycles. Two full-flow bleeds, each lasting several days, roughly three weeks apart, reads as a shortened cycle. A normal period followed ten days later by a few days of light bleeding reads as intermenstrual bleeding, and if that pattern repeats, it is the one to raise with a clinician rather than wait out.
Perimenopause heavy periods: how heavy is too heavy?
Heaviness is the change women tolerate longest and report latest, partly because ‘heavy’ is a comparison with their own past rather than a measurement. Clinicians have tried to put numbers on it, and the thresholds are useful.

The NHS describes heavy menstrual bleeding as needing to change a pad or tampon every one to two hours, passing clots larger than a quarter, bleeding through clothes or bedding, needing to double up on protection, or bleeding for more than seven days. Mayo Clinic adds the overnight test: having to get up to change protection during the night. Any one of these on a recurring basis counts, even if the total number of days has not changed.
Why does flow climb during the transition? Two reasons dominate. The first is the unopposed-estrogen effect described earlier: cycles without ovulation let the lining grow thicker than usual, and a thicker lining means more tissue and more blood when it sheds. The second is that conditions which cause heavy bleeding at any age, fibroids and adenomyosis in particular, peak in prevalence in the 40s. Fibroids are benign muscular growths in the uterine wall; adenomyosis is lining tissue growing into that wall. Both are common, both can enlarge the bleeding surface, and perimenopause often happens to arrive at the same time.
The cost of heavy periods is rarely the bleeding itself. It is the iron lost with it, which we cover in a later section, and the quiet rearranging of life around flow: dark clothes, mapped bathrooms, declined invitations. Those adaptations are a sign that the bleeding is heavy enough to warrant a conversation, regardless of whether hormones or structure turn out to be the explanation. Heavy perimenopause periods are common, but common is not the same as something you are obliged to endure.
Perimenopause spotting: hormonal or something else?
Spotting, meaning light bleeding that does not require more than a liner, is a frequent companion of the transition. Data from a large US cohort that followed women through perimenopause found that most reported at least one episode of spotting lasting six or more days, and many reported several. In other words, it is the rule rather than the exception.
The hormonal version has a few typical shapes. Brown or pink spotting in the two or three days before a period starts, often because progesterone is dropping early and the lining begins to come away before the main shed. Spotting around mid-cycle, when the estrogen peak that precedes ovulation briefly dips. Scattered days of light bleeding in a long gap between periods, when an unovulatory cycle sheds a little lining at a time instead of all at once.
Spotting that behaves differently warrants a different response. Bleeding after sex, called postcoital bleeding, points toward the cervix or vaginal tissue rather than the hormonal rhythm. Spotting that appears on most days, or follows no pattern at all for more than a cycle or two, can come from a polyp, a small growth of lining tissue that bleeds easily. Spotting in a woman using hormonal contraception or hormone therapy often reflects the medicine itself, which is a reason to tell the prescriber, not to adjust or stop anything on your own.
One further distinction is worth stating plainly. Spotting during perimenopause, while periods are still happening, is usually benign. Spotting after menopause, once 12 months have passed without a period, is treated differently. Postmenopausal bleeding of any amount is evaluated promptly, because it is the most common presenting sign of endometrial cancer, even though most women who have it turn out to have a benign cause.
Longer gaps and skipped months: the late transition
At some point the pattern tips from too frequent to too infrequent. Cycles stretch to 40, 50, 60 days. A month passes with nothing, then a period arrives that may be unremarkable or unusually heavy, because the lining had longer to build. Staging systems mark the late transition as the point at which a gap of 60 days or more occurs, and from there the final period is typically one to three years away.
The gaps are not a smooth taper. Periods tend to go quiet, return, go quiet again. Hot flashes and night sweats usually intensify in this phase, since estrogen levels drop lower for longer between the remaining ovulations. Sleep often suffers accordingly.
Two practical consequences follow. The first is that you cannot know a period was your last until a year has passed. A gap of eight or nine months followed by a bleed resets the clock, and it does not mean anything has gone wrong.
The second concerns pregnancy. Ovulation becomes rare in the late transition but does not stop until it stops, and the long gaps make it impossible to predict. NHS guidance is that contraception should continue until 12 months after the last period in women over 50, and until two years after the last period in women under 50, unless a clinician advises otherwise. Fertility is low in the late 40s, but low is not zero, and an unexpected pregnancy in this phase carries higher risks than one a decade earlier.
If a very long gap is followed by prolonged or heavy bleeding, that is a reasonable moment to seek an examination even if everything turns out to be hormonal. A lining that has grown for several months can be assessed with an ultrasound, and the reassurance is worth having.
What changed recently
The biology of perimenopause periods has not changed. The conversation around it has, and a few dated markers explain why the topic feels newly urgent.
In October 2024 the World Health Organization updated its menopause fact sheet, framing the transition as a normal life stage that nonetheless deserves information and care, and noting that many women worldwide lack access to accurate guidance about the symptoms, including bleeding changes. The same year the UK national guideline on menopause was revised (November 2024), with a stronger emphasis on recognizing perimenopause by symptom and cycle pattern rather than waiting for periods to stop. In November 2025 the US Food and Drug Administration announced revisions to the boxed warnings on menopausal hormone therapy labels, a change that concerns treatment decisions and belongs in a conversation with a prescribing clinician rather than in a social feed.
Consumer health publishers have followed. Cleveland Clinic and Mayo Clinic both maintain updated perimenopause pages that list irregular periods first among symptoms, and the NHS has expanded its heavy periods guidance with concrete thresholds for what counts as heavy.
The other shift is cultural. Women in their 40s now talk openly about cycle changes on video platforms, and that openness is a net good. The downside is compression: a two-minute clip can convey that heavy periods are normal in perimenopause without the clause that follows in every guideline, which is that certain patterns are evaluated regardless of age. The viral message and the clinical message overlap by about 80 percent. This article is mostly about the remaining 20.
None of these developments alters the core advice. Track your cycles, know the red flags, and bring the pattern to someone who can examine you. What is new is that more women are asking the question early, and that is precisely the point at which asking helps.
What the evidence actually says, and how strong it is
Not every statement in this article rests on the same footing, so here is the grading.
Cycle patterns during the transition: strong observational evidence. The sequence of shortening, irregularity and lengthening comes from large prospective cohorts, most notably a multi-ethnic US study that followed thousands of women with menstrual diaries for more than a decade. Cohorts cannot prove cause, but when the same pattern appears across thousands of women and multiple countries, the description is reliable. The staging thresholds (seven days of variability, 60-day gaps) were derived from this kind of data by expert consensus.
Frequency of heavy and prolonged bleeding: strong observational evidence. The same cohort reported that a large majority of women experienced at least one episode of bleeding lasting ten or more days during the transition, and roughly a third had three or more such episodes. That is why clinicians regard a single long bleed as expected and a repeated pattern as worth a closer look.
Thresholds for ‘heavy’: expert consensus informed by measurement studies. The pad-every-hour rule and the quarter-sized clot rule correlate with measured blood loss above 80 milliliters per cycle in older research, but the cutoffs are pragmatic rather than precise.
Postmenopausal bleeding as a cancer signal: strong observational evidence. Pooled analyses show that around nine in ten women with endometrial cancer present with bleeding, while roughly one in ten women with postmenopausal bleeding has the cancer. Both numbers justify prompt evaluation without justifying panic.
Treatments for heavy bleeding: randomised trials exist. Hormonal and non-hormonal options have been compared head to head in trials, which is a higher grade of evidence than most of the above. Which option fits a particular woman depends on her examination, her other health conditions and her wishes, and that decision rests with the treating clinician.
Normal perimenopause periods versus patterns that need checking
The table below compresses the guidance into one place. It is a prompt for a conversation, not a tool for self-diagnosis; the right-hand column means ‘book an appointment’, not ‘assume the worst’.
| Pattern | Usually part of the transition | Worth a clinical check |
|---|---|---|
| Cycle length | Varies by a week or more; shortens to 21–24 days, later stretches past 35 | Cycles consistently under 21 days with full-flow bleeds |
| Duration of bleeding | Occasional period of 7–10 days | Repeated bleeds beyond 7 days, or any bleed lasting 2 weeks or more |
| Heaviness | Some months heavier than your old normal | Soaking protection hourly for 2+ hours, clots larger than a quarter, changing overnight |
| Spotting | A few days before a period or around mid-cycle | Bleeding after sex; spotting on most days; new spotting on hormone therapy |
| Gaps | Skipped months, gaps of 60 days or more | Bleeding of any amount after 12 period-free months |
| How you feel | Tired around the period | Breathlessness on stairs, dizziness, pounding heartbeat, pale skin |
Two features cut across every row. The first is persistence: one odd cycle is noise, three in a row is a pattern. The second is change in a different direction from the expected one. Perimenopause tends to push cycles apart over time; a pattern that keeps getting closer together and heavier, year on year, is moving against the current and is easier to explain by something other than hormones.
Age modifies the reading as well. Irregular, heavy bleeding at 43 is more often hormonal than the same pattern at 53, when ovulation has largely ceased and a thickened lining is more likely to reflect a structural cause. Clinicians weigh this routinely; it helps if you know they are doing it.
What else causes heavy or irregular bleeding in your 40s?
Perimenopause has a habit of taking credit for every bleeding change in the decade, and that is the main risk of the viral narrative. Several other conditions peak at exactly the same age and produce overlapping symptoms.
Fibroids are the most common. By their late 40s a majority of women have at least one, though many never notice. Fibroids that press into the uterine cavity enlarge the bleeding surface and can cause heavy, prolonged periods with large clots, along with pelvic pressure or a need to urinate more often. Adenomyosis, in which lining tissue grows into the muscular wall, produces heavy painful periods and a tender, slightly enlarged uterus; it is often found alongside fibroids.
Polyps are small outgrowths of lining tissue that bleed easily and irregularly. Spotting between periods, after sex or after exercise is their typical calling card.
Endometrial hyperplasia is a thickening of the lining driven by estrogen without enough progesterone. Perimenopause itself creates that imbalance, and so do excess body weight, polycystic ovary syndrome and some medicines. Hyperplasia is not cancer, but some forms can progress toward it, which is why a lining that stays thick on ultrasound is usually sampled.
Thyroid disease deserves a mention because an underactive thyroid can cause heavy periods and an overactive one can cause light or absent ones, and both are more common in midlife women. A simple blood test separates them from perimenopause.
Bleeding disorders, most often von Willebrand disease, can surface late if periods were always heavy and no one asked. Certain medicines, including blood thinners, influence flow too. And cervical causes, from benign ectropion to abnormal cells, present as bleeding after sex, which is why staying current with cervical screening remains part of the picture in this decade.
None of this means perimenopause is a diagnosis of exclusion. It means it is a diagnosis made with eyes open to its neighbors.
Iron, anemia and the hidden cost of heavy periods
A woman loses roughly 30 to 40 milliliters of blood in a typical period and several times that in a heavy one. Every milliliter carries about half a milligram of iron. Over a year of heavy perimenopause periods, that drain can outpace what a reasonable diet replaces, and iron stores fall long before the hemoglobin count follows. The result is often misread as the fatigue of midlife rather than a deficiency with a cause.
Iron-deficiency anemia announces itself quietly. Tiredness that sleep does not fix, breathlessness on a flight of stairs that used to be nothing, a racing or pounding heartbeat, headaches, feeling cold, brittle nails, restless legs at night, and in some women a craving to chew ice. Paler skin and the inside of the lower eyelid losing its usual pink are physical signs a clinician will look for.
The NIH Office of Dietary Supplements notes that women of reproductive age are among the groups most likely to run short of iron, and heavy menstrual bleeding is the leading reason. The diagnosis is straightforward: a complete blood count measures hemoglobin and red cell size, and a ferritin test measures stored iron. Ferritin can be low while hemoglobin is still normal, which is early deficiency and still worth treating.
Treatment is a clinical decision rather than a supermarket one. Iron supplements come in different forms and strengths, interact with some foods and medicines, and can cause digestive side effects that make people stop; a clinician can match the choice to the blood results and recheck them. Taking iron ‘just in case’ without a test is not advisable, because iron overload has its own harms and because a normal result would point attention back to the bleeding itself.
The larger point is that anemia is a consequence, not a condition to manage in isolation. Bleeding heavy enough to cause it is bleeding heavy enough to evaluate.
What are the signs perimenopause is coming to an end?
There is no finish-line signal, which frustrates people who have tracked every cycle for years. The end is recognized in hindsight, 12 months after the last period, and nothing in the body announces that a particular bleed is the final one. That said, the late transition has a recognizable texture.
Gaps lengthen and the quiet stretches grow. Once you have had a gap of 60 days or more, the final period is on average one to three years away, although the range is wide. Periods that do arrive may be lighter and shorter, or, after a long gap, heavier than usual; both are consistent with the stage.
Vasomotor symptoms, the clinical term for hot flashes and night sweats, usually peak in the year or two around the final period and then slowly ease, though for a sizeable minority they continue for years afterward. Vaginal dryness and urinary urgency tend to appear or worsen as estrogen settles at its lower level, and unlike hot flashes they do not fade on their own.
Sleep often improves once the hormonal swings flatten, and some women describe a sense of the weather settling even before periods have fully stopped. Mood symptoms tied to the fluctuations frequently ease at the same point.
Hormone tests have limited value here. FSH can be high one month and lower the next while periods are still occurring, so a single raised value does not confirm that the end is near, and guidelines generally advise against using it for that purpose in women over 45. The calendar is the better instrument.
Two caveats keep the picture honest. Contraception needs continue until the 12-month mark (or longer if under 50). And any bleeding after that mark, however light, is postmenopausal bleeding and is assessed, because the rules change the day the transition ends.
Common myths about perimenopause periods
The viral claims mostly contain a kernel of truth wrapped in an overstatement. Here are the ones worth unwrapping.
‘Two periods a month confirms perimenopause.’ It is consistent with the early transition, and at 45 it is the most likely explanation. It is not a confirmation, because polyps, fibroids, thyroid disease and intermenstrual bleeding from other causes produce the same calendar. Confirmation comes from the pattern over several months and, where needed, an examination.
‘Heavy bleeding in your 40s is normal, so just wait it out.’ Heavier periods are common in perimenopause; bleeding that meets the thresholds for heavy is still evaluated, because the explanation changes what helps and because the iron loss accumulates whether or not the cause is hormonal.
‘A blood test can tell you where you are.’ FSH fluctuates week to week during the transition. One high value does not stage you, and guidelines do not recommend routine testing for diagnosis after 45. Your cycle diary is more informative than a single lab result.
‘Periods fade gradually and then stop.’ For some women, yes. For many, the path is shorter cycles, then chaos, then long gaps punctuated by occasional heavy bleeds. Irregular is the expected shape.
‘You cannot get pregnant once periods are irregular.’ Ovulation becomes unpredictable, not impossible. Contraception is advised until 12 months after the last period, or two years if you are under 50.
‘Spotting is always harmless at this age.’ Spotting before a period or at mid-cycle usually is. Bleeding after sex, spotting on most days, or any bleeding after 12 period-free months is examined, not explained away.
Each correction points the same direction: the transition is real and mostly benign, and the small set of exceptions is defined clearly enough that you can recognize them.
When to see a doctor about perimenopause periods
Most of what this article describes is something to track and discuss at a routine visit. A smaller set of patterns should prompt an appointment in the near term, and a few need same-day care.
Book an appointment soon if you notice:
- bleeding that soaks through a pad or tampon every hour for two or more hours in a row
- periods lasting longer than seven days on a repeated basis, or any bleed continuing for two weeks
- clots larger than a quarter, or bleeding that regularly comes through clothing or bedding
- bleeding after sex, or spotting between periods that persists beyond one or two cycles
- cycles that consistently arrive less than 21 days apart with full flow
- any bleeding at all after 12 months without a period
- new or worsening pelvic pain or pressure, or a sense of fullness in the lower abdomen
- symptoms of iron deficiency: breathlessness on exertion, dizziness, a pounding heartbeat, unusual pallor or persistent exhaustion
Seek urgent or emergency care if bleeding is very heavy and accompanied by faintness, chest pain, severe breathlessness or a rapid heartbeat, or if severe pelvic pain develops suddenly, particularly if there is any chance of pregnancy.
At the appointment, expect to be asked for dates, duration and heaviness over recent cycles, which is where a tracking app or a paper calendar earns its keep. A clinician will usually perform a pelvic examination, check that cervical screening is current, and order a blood count with ferritin and often a thyroid test. A transvaginal ultrasound measures the lining and looks for fibroids and polyps. If the lining is thick or the pattern is concerning, a small sample (an endometrial biopsy) can be taken in the clinic to examine the cells directly.
Management, once a cause is clear, ranges from reassurance and iron correction to hormonal and non-hormonal options for reducing flow, and in some cases procedures for fibroids or polyps. Which route suits you depends on findings, other health conditions, contraceptive needs and your own preferences, and every one of those choices belongs in a conversation with the clinician who has examined you. The job of this article was to get you to that conversation with the right questions.
Frequently asked questions
What does a perimenopausal period look like?
It varies month to month, which is the defining feature. Cycles often shorten by several days first, then become irregular, with some periods lighter and shorter and others heavier, clottier and longer than before. Brown spotting before the main flow is common, and premenstrual symptoms can feel sharper. Gradual tapering happens for some women, but an unpredictable pattern is at least as typical.
Why am I having two periods a month at 45 years old?
Most often because your cycle has shortened to around 21–24 days, so two bleeds fall within one calendar month. Rising follicle-stimulating hormone in early perimenopause speeds up the first half of the cycle. If one of the two bleeds is light and arrives roughly ten days after a normal period, that is bleeding between periods, and if it repeats it should be assessed rather than assumed to be hormonal.
Are perimenopause heavy periods normal, or should I get them checked?
Heavier periods are common in perimenopause because cycles without ovulation let the lining grow thicker. They are still checked when they meet the thresholds for heavy bleeding: soaking a pad or tampon hourly for two or more hours, clots larger than a quarter, bleeding through clothes or overnight, or lasting beyond seven days. Fibroids, polyps and thyroid problems peak at the same age and can be treated.
What is perimenopause spotting and when is it a concern?
Spotting is light bleeding that needs no more than a liner. During perimenopause it commonly appears a few days before a period or around mid-cycle, when hormone levels dip, and that pattern is usually benign. Spotting after sex, spotting on most days, new spotting while using hormone therapy, or any bleeding after 12 period-free months should be evaluated by a clinician.
When should I worry about my period during perimenopause?
Worry is rarely useful, but a prompt appointment is warranted for bleeding that soaks protection hourly for two hours, lasts beyond seven days repeatedly, includes clots larger than a quarter, occurs after sex, or returns after 12 months without a period. Faintness, chest pain or severe breathlessness alongside heavy bleeding needs urgent care. Persistent patterns matter more than one odd cycle.
What are the signs perimenopause is coming to an end?
Gaps between periods lengthen, often to 60 days or more, and the final period typically follows within one to three years of that first long gap. Hot flashes and night sweats tend to peak around this time, while vaginal dryness may begin. The end itself is only confirmed in hindsight, 12 months after the last bleed; no test reliably predicts it.
Can a blood test confirm perimenopause?
Not reliably. Follicle-stimulating hormone rises during the transition but swings widely from week to week, so a single reading can be high one month and lower the next while periods continue. Guidelines generally advise against routine hormone testing for diagnosis in women over 45 with typical symptoms. A record of your cycle lengths and symptoms over several months is more informative.
How long do perimenopause periods stay irregular?
The transition lasts about four years on average and up to eight to ten for some women, with irregular periods for much of that time. Shorter cycles usually appear first, followed by unpredictable spacing and then progressively longer gaps. Irregularity ends only with the final period, which is recognized once 12 consecutive months have passed without bleeding.
Can I still get pregnant with irregular perimenopause periods?
Yes. Ovulation becomes infrequent and unpredictable but does not stop until the final period, and long gaps make it impossible to know which cycles are fertile. NHS guidance is to continue contraception until 12 months after the last period in women over 50, and for two years after it in women under 50, unless a clinician advises otherwise.
What tests will a doctor do for heavy or irregular bleeding in my 40s?
Typically a pelvic examination, a check that cervical screening is up to date, and blood tests including a full blood count, ferritin for iron stores and often thyroid function. A transvaginal ultrasound measures the uterine lining and looks for fibroids or polyps. If the lining is thickened or the pattern is concerning, a small endometrial biopsy may be taken in the clinic.
References
- NHS: Heavy periods
- Cleveland Clinic: Perimenopause
- World Health Organization: Menopause fact sheet
- NHS: Menopause symptoms
This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.
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