Irregular bleeding in midlife: what is expected and what needs checking

Perimenopause makes bleeding unpredictable on purpose. That is a genuinely difficult situation to assess from the inside, because the ordinary rule of thumb, that a change in your pattern is worth checking, stops working when change is the pattern.

So here are the thresholds that clinicians actually use. Some are firm rules. One of them is absolute.

What is expected

Changes to your periods are usually the first sign of perimenopause. They may come more often or less often, and bleeding may get heavier or lighter, before stopping altogether ¹.

The NHS describes this as a natural part of life, driven by falling hormone levels, usually affecting women between 45 and 55 but sometimes earlier ⁷.

A gap of 60 days or more between periods is a recognised marker: in the STRAW+10 staging system it defines the late menopausal transition ⁵. Cycles in that stage are characterised by increased variability in length, extreme fluctuations in hormone levels, and a higher rate of cycles without ovulation ⁵.

That last point explains most of the mess. When you do not ovulate, the progesterone phase that normally ends a cycle on schedule does not happen, so the lining sheds when it runs out of support rather than on a timetable.

So: cycles shortening to three weeks, then a seven-week gap, then a heavier bleed. Unpleasant, and within the expected range.

What needs an appointment

Bleeding more rather than less

The NHS advises contacting your GP if you still have periods but your bleeding pattern has changed and you are bleeding more, not less, than before ¹.

This is the perimenopausal rule most worth remembering. The trend of the transition is towards less bleeding overall. A trend in the other direction is worth a look.

Heavy periods, defined properly

"Heavy" is subjective, so the NHS gives countable markers. You may have heavy periods if you need to change your pad or tampon every one to two hours, or empty a menstrual cup more often than recommended; need to use two types of period product together; have periods lasting more than seven days; pass blood clots larger than about 2.5cm; bleed through to your clothes or bedding; avoid daily activities or take time off work because of your periods; or feel tired or short of breath a lot ³.

That last item is the one people ignore. Persistent tiredness and breathlessness alongside heavy bleeding can indicate iron deficiency anaemia, and blood tests to check for underlying conditions including anaemia are part of the standard workup ³.

Heavy periods can be normal for you, and can be heavier at particular times including approaching menopause ³. But they can also be caused by fibroids, endometriosis, adenomyosis, pelvic inflammatory disease, polycystic ovary syndrome, bleeding disorders such as Von Willebrand disease, or certain medicines including anticoagulants and chemotherapy drugs. Rarely, heavy periods can be a sign of womb cancer ³.

The NHS advises seeing a GP if heavy periods are affecting your life, if you have had them for some time, if you have severe pain during your periods, if you bleed between periods or after sex, or if you have heavy periods alongside pain when peeing, opening your bowels or having sex ³.

Treatments exist and do not have to start with surgery. Options from a GP include an intrauterine system or the combined pill, tranexamic acid to reduce bleeding, and prescription anti-inflammatory painkillers such as mefenamic acid or naproxen. If those do not work or a condition is suspected, referral follows ³.

Bleeding between periods, or after sex

Both are on the NHS list of reasons to see a GP about heavy periods, alongside severe period pain and pain when peeing or opening your bowels ³. Bleeding after sex is also a reason to be seen if you have vaginal dryness [see the article on vaginal dryness and GSM on this site].

Bleeding on HRT: the timeframes that matter

This is where a lot of women either panic unnecessarily or wait too long, because nobody gave them the window.

NICE tells clinicians to explain to people with a uterus that vaginal bleeding is a common side effect during two specific periods: during the first six months of taking systemic HRT, or within any three months of changing the dose or preparation of systemic HRT. It also says they will be asked about this at their three-month review, and advises seeking medical help promptly if unscheduled vaginal bleeding occurs beyond those timeframes ⁴.

The NHS version of the same point is that taking HRT during perimenopause can make periods more regular, that you may have some irregular bleeding or spotting, and that this should settle within six months, and to talk to a GP if you are taking HRT and still having irregular or heavier bleeding or spotting after six months ¹.

Two practical consequences.

First, the date you started HRT and the date of every dose or preparation change are worth writing down. Those dates are what determine whether bleeding is inside the expected window or outside it, and they are exactly the dates nobody remembers accurately.

Second, NICE acknowledges that the evidence for people who experience unscheduled bleeding on sequential or continuous HRT is limited, and points to British Menopause Society guidance on managing it ⁴. If your clinician is uncertain, that uncertainty is documented in the guideline, not a failing.

After menopause, there is one rule

Menopause is usually diagnosed in women over 45 who have not had a period for more than a year. Any bleeding from the vagina after that point needs to be checked by a GP ².

There is no version of this that waits.

See a GP: postmenopausal bleeding

See a GP if you have postmenopausal bleeding, even if it has only happened once, even if there is only a small amount of blood, spotting, or pink or brown discharge, even if you have no other symptoms, and even if you are not sure it is blood ².

Postmenopausal bleeding is not usually serious, but it can be a sign of cancer, and cancer may be easier to treat if it is found early ².

Your GP should refer you to hospital or to a specialist postmenopausal bleeding clinic, and you should not have to wait more than two weeks to see a specialist ².

What happens at the appointment

Knowing the process removes some of the fear.

At the specialist clinic, which may be run by a nurse, you will be offered tests to find the cause. These may include a vaginal ultrasound scan using a small device placed in the vagina; an examination of the pelvis and vagina, possibly using a speculum so the vagina and cervix can be seen; a hysteroscopy, where a thin camera is passed through the cervix into the womb to look for problems and take a tissue sample for testing, under local or general anaesthetic; and an examination in which the specialist presses on your abdomen and inside the vagina to check for lumps or tenderness ².

The most common causes are inflammation and thinning of the vaginal lining or womb lining caused by lower oestrogen levels; cervical or womb polyps, which are usually not cancerous; and a thickened womb lining, which can be caused by HRT, high oestrogen levels or being overweight, and which can lead to womb cancer. Less commonly, postmenopausal bleeding is caused by cancer, including ovarian and womb cancer ².

Treatment depends on the cause and ranges from no treatment at all, through oestrogen cream or pessaries for vaginal or endometrial atrophy, through removal of polyps, through changing or stopping HRT, to surgery and oncological treatment for cancer ².

Two things that complicate the picture

Hormonal contraception makes bleeding a poor guide to your stage. The progestogen-only pill, hormonal coil, implant and injection can make periods irregular or stop them entirely, while the combined pill produces monthly bleeds for as long as you take it ¹. NICE also notes that it can be difficult to identify menopause in people taking hormonal treatments, for example for heavy menstrual bleeding ⁴.

Hysterectomy and endometrial ablation remove bleeding as a signal altogether. STRAW+10 notes that women who have had either cannot be staged by menstrual bleeding criteria and can only be assessed using hormone markers, with a recommendation to wait at least three months after surgery before assessing hormone status ⁵.

Contraception, because this is where it gets forgotten

Pregnancy is still possible during perimenopause. The WHO recommends contraception until twelve consecutive months without menstruation ⁶. The NHS gives age-specific advice: contraception for one year after your final period if you are 50 or over, and for two years if you are aged 40 to 49 ¹.

The combined pill is not recommended from age 50, because the risks generally outweigh the benefits, and a GP may suggest progestogen-only contraception instead ¹.

HRT is not a contraceptive ⁴.

Guidance in the US

The American College of Obstetricians and Gynecologists (ACOG) says bleeding after menopause needs prompt evaluation, because vaginal bleeding is the first sign in more than 90% of postmenopausal women with womb (endometrial) cancer ⁸. It describes a transvaginal ultrasound showing a thin womb lining, 4 mm or less, as usually sufficient for a first assessment, and says persistent or recurring bleeding needs further testing even if a first biopsy was normal ⁸.

When the FDA removed several boxed warnings from hormone therapy in 2025, it kept the boxed warning about endometrial cancer for systemic estrogen-alone products ⁹, the same risk that makes a progestogen necessary if you have a womb.

What is still uncertain

The main gap is the one NICE names: limited evidence on how to manage unscheduled bleeding in women taking sequential or continuous HRT ⁴. Practice in this area rests substantially on specialist society guidance rather than large trials.

There is also no reliable way to predict, from your bleeding pattern alone, when your final period will be.

The record that makes this appointment easier

For bleeding, a written record does more work than for almost any other symptom, because everything a clinician wants to know is a date or a number: when each bleed started and stopped, roughly how heavy, whether you passed clots, whether it happened after sex, and the date of every HRT change.

A wall calendar with marks on it is sufficient. If you would rather it were on your phone, Halcyon records bleeding days and dose changes on the same timeline. Either way, the record is the point.