Perimenopause and menopause: ages, hormones and symptoms

Premenopause, perimenopause and menopause — what is the difference?

Premenopause describes the reproductive years before the menopause transition. With ovulatory cycles, oestrogen and progesterone rise and fall in a repeating pattern. Progesterone rises after ovulation; oestrogen has peaks at different points in the cycle.

Perimenopause is the transition leading up to menopause and includes the first year after the final period. It often begins in the 40s, although some women notice changes earlier. On average it lasts around four years, though it can be shorter — or run eight years or more. Ovulation becomes less predictable, progesterone production becomes less consistent, and oestrogen can swing sharply — sometimes high, sometimes low. It is not simply a smooth decline in every hormone.

Menopause is the final menstrual period, recognised retrospectively after 12 months without a period when there is no other explanation and you are not using hormonal contraception that changes bleeding. Natural menopause usually occurs between 45 and 55, with an average around 51 in many European populations. Postmenopause is the time after that final period, when ovarian oestrogen and progesterone generally remain lower.

Menopause between 40 and 44 is called early menopause. Before 40, loss of ovarian function may be premature ovarian insufficiency (POI), which needs assessment and has different implications for treatment and long-term health. Surgery and some cancer treatments can also bring on menopause earlier or more abruptly.

Symptoms: much more than hot flushes

Changes in periods are often an early clue: cycles may shorten or lengthen, bleeding may become heavier or lighter, and periods may be missed. Hot flushes and night sweats are common, but they are only part of the picture.

Women may experience disrupted sleep, fatigue, anxiety, low mood, irritability, brain fog, difficulties with concentration, headaches, joint or muscle aches, and changes in sexual desire. Vaginal dryness, pain with sex, urinary urgency and recurrent urinary infections can also develop and may persist after menopause. Some women have few symptoms; others find work, relationships and daily life profoundly affected.

These symptoms are not unique to menopause. Thyroid disease, iron deficiency, depression and other conditions can overlap, so an assessment should look at the whole person rather than assume every symptom is hormonal. For most otherwise healthy women aged 45 or over with a typical history, diagnosis is clinical; fluctuating hormone levels mean a single blood test is often unhelpful. Younger women or atypical symptoms may need tests.

Very heavy or persistent unusual bleeding deserves medical review. Any bleeding after menopause should be assessed, rather than put down to ‘just hormones’.

Bring to your consultation

• A note of your period pattern, symptoms and how they affect everyday life.
• Your medicines, contraception, and personal and family medical history.
• The questions that matter to you: benefits, risks, bleeding, treatment options and follow-up.

References

1. NICE. Menopause: identification and management (NG23).
2. NHS. Menopause and perimenopause: symptoms.