Perimenopause: stages, symptoms and evidence-graded options

Perimenopause is the biological transition phase preceding menopause, typically beginning between ages 40 and 45 and lasting four to eight years on average. During this interval, ovarian follicle depletion causes erratic surges and drops in estrogen and progesterone, rather than a steady decline.

Understanding where you are in this transition helps you make sense of daily changes and choose effective treatments.

The two stages of the menopause transition

Clinical consensus defined by the STRAW+10 criteria classifies the transition into two distinct stages:

1. Early transition: Menstrual cycles remain regular or vary by seven or more days between consecutive periods. You might experience subtle mood changes, lighter or heavier bleeding, or initial sleep disruptions.
2. Late transition: Skipped cycles of 60 days or more occur. Vasomotor symptoms like hot flashes and night sweats usually become more frequent and pronounced during this phase.

Recognizing early symptoms

Symptoms often appear while periods are still relatively regular. Common early indicators include:

• Shorter cycle length (for instance, dropping from 28 days to 23 days).
• Sudden waking at 3 a.m. with rapid heartbeat or sweating.
• Premenstrual mood swings or anxiety that feel more intense than past years.
• Slower cognitive processing or word retrieval during busy workdays.

Read our detailed breakdown in the Early signs of perimenopause guide and compare how the transition differs from the final period in Perimenopause vs menopause: what is the difference?. For how symptoms actually unfold over calendar time — not just by cycle stage — see what to expect year by year.

Diagnosing perimenopause: do you need a blood test?

A common question is whether a blood test can prove you are in perimenopause. Major clinical guidelines, including NICE and The Menopause Society, advise against routine hormone blood tests (such as FSH or estradiol) in women aged 45 and over. See our full guide on Is there a blood test for perimenopause?.

Because hormone levels fluctuate widely from day to day and even hour to hour during perimenopause, a single blood draw does not provide a reliable diagnosis. Instead, diagnosis is based on your age, cycle history, and symptom patterns.

Since periods can still be happening irregularly rather than absent, pregnancy remains possible throughout this stage — see our guide to contraception in perimenopause for what a 2025 expert consensus recommends.

Preparing for your appointment

When consulting your healthcare professional, bring concrete documentation rather than generalized impressions:

• Complete the Perimenopause symptoms checklist to record all active symptoms.
• See how STRAW+10 cycle rules apply with our Perimenopause stage guide, or track period gaps with the 12-month period-free counter.
• Review our suggested questions in What to ask your doctor about perimenopause.
• Track two weeks of sleep, bleeding, and vasomotor episodes with the daily and weekly symptom log.
• Check clinical trial evidence on popular supplements in Does magnesium help menopause symptoms?.

Further reading

For an evidence-based, myth-busting breakdown of the biology, symptoms, and medical options of the menopause transition, read our review of The Menopause Manifesto by Dr Jen Gunter.