Perimenopause at 45: squarely normal, and often dismissed anyway

This is the middle of the distribution

With an average final period at 51 and an average perimenopause of around four years, 45 sits comfortably inside the expected window. It is not early, it is not borderline, and it does not require an explanation.

That is worth stating plainly because the experience many women report at this age is being treated as though they had proposed something unlikely.

What the first signs look like

The formal marker of early perimenopause is a persistent change in cycle length of seven days or more, in either direction. Cycles commonly shorten first, so periods arriving every 24 days instead of 28 is a change, not a non-event.

Alongside or before that:

• Heavier or more clotted bleeding, or unusually light periods
• Sleep breaking at three or four in the morning
• New or intensified premenstrual mood symptoms, particularly irritability
• Hot flashes, which may be mild and easy to dismiss at this stage
• Anxiety arriving with a physical rather than a psychological quality
• Joint aches and stiffness, worst on waking

Why no blood test is needed

NICE guidance states that in women over 45 with typical symptoms, perimenopause should be diagnosed without laboratory tests. The reason is straightforward: FSH and estradiol swing so widely day to day in this phase that a single measurement carries almost no information.

The practical consequence matters more than the principle. A normal FSH at 45 does not rule perimenopause out. If you are told your bloods are normal so this is not menopause, that conclusion does not follow from that result, and it is reasonable to say so.

One genuine exception: if you have no periods to assess, because of a hysterectomy or a hormonal coil, testing regains its value.

Contraception still matters

Perimenopause reduces fertility but does not end it. Pregnancy remains possible until twelve months after the final period for women over 50, and twenty-four months for women under 50.

This catches people out at exactly this age, partly because irregular cycles make the usual timing assumptions unreliable.

When to see someone

Any symptom interfering with work, sleep or relationships is reason enough, and no test result needs to justify it first.

Bring a cycle record for the past twelve months, since that is what the diagnosis actually rests on at this age. Flag heavy bleeding separately: it is common in perimenopause but it is also the symptom most worth examining on its own terms.