Your period still arrives almost to schedule. Yet you wake drenched in sweat, sleep less well or notice that your flow has changed. Could this be perimenopause? Yes: regular periods do not rule out early signs. One symptom is not enough; what matters is a new pattern involving symptoms, bleeding, age and health context.

What is perimenopause?

Perimenopause is the transition leading up to your final menstrual period. During this time, oestrogen and progesterone fluctuate more, even though ovulation and regular bleeding may continue. Menopause itself can only be confirmed retrospectively, after 12 consecutive months without a natural period. Your body may therefore be responding to the transition while your calendar still looks reassuringly predictable.

Why can periods remain regular?

The commonly used STRAW+10 criteria identify the early menopausal transition mainly when the length of consecutive cycles repeatedly differs by at least seven days. This is a useful objective marker, but it does not describe every woman equally well. Newer research suggests that typical symptoms and a change in menstrual flow may appear earlier. This evidence adds to cycle tracking; it does not replace a clinical assessment.

Which early signs of perimenopause matter most?

• Hot flushes and night sweats: when these are new, they are among the most informative clues that the transition may be beginning.
• A different flow with the same timing: periods may become heavier, lighter, longer or shorter even while they remain regular.
• Vaginal dryness or discomfort during sex: changes in the vaginal and genital tissues may begin early, and treatment is available.
• Disturbed sleep: night sweats may wake you, although insomnia also has many causes unrelated to perimenopause.
• Mood, concentration or body changes: irritability, low mood, brain fog, palpitations or aching joints are reported, but none is specific enough to identify perimenopause alone.

None of these signs proves that you are in perimenopause. Look at when they began, how often they occur, which symptoms cluster and how they affect daily life. Thyroid problems, iron deficiency, pregnancy, medicines, stress and other conditions can cause similar symptoms.

What can you do now?

• Track for four weeks: record the first day of each period, flow and duration, hot flushes, night sweats, sleep, mood and the impact on your day.
• Keep it simple: use a 0-to-3 rating for each symptom. Add possible triggers such as alcohol, spicy food, heat or an unusually stressful day.
• Ease the immediate moment: wear light layers, keep the bedroom cool and have water or a change of clothing ready if night sweats wake you.
• Prepare for an appointment: take your notes and a list of medicines, supplements and contraception to your GP or gynaecologist.

What may help over time?

Regular movement, strength training, a consistent sleep routine, balanced food and reducing smoking or alcohol support your general health and may improve individual symptoms. They are not a diagnostic test for perimenopause. If symptoms are affecting your quality of life, ask about hormonal and non-hormonal treatment options. The balance of benefits and risks depends on your symptoms, age, medical history, medicines and preferences.

A single hormone result often cannot confirm or exclude perimenopause because FSH and oestrogen can fluctuate markedly. The pattern over time, symptoms and bleeding history are often more useful. If you are under 45, and especially under 40, a targeted medical assessment is important. Ovulation and pregnancy remain possible during perimenopause, so regular or irregular periods are not a substitute for contraception.

When should you seek medical advice?

Book an appointment if new symptoms persist, noticeably affect you or leave you uncertain. Bleeding should be checked promptly if it is very heavy, lasts longer than seven days, happens between periods or after sex, or is markedly different from usual. Seek urgent help if heavy blood loss comes with dizziness, breathlessness or fainting. Any bleeding after 12 months without a period needs medical assessment.

Please also have marked palpitations, unexplained weight change, severe pain or extreme tiredness assessed rather than assuming menopause is the cause. Persistent depression or anxiety is treatable. If you are thinking about harming yourself or someone else, contact emergency medical services or a crisis service immediately.

What does the research say?

The Australian Women’s Midlife Years Study, published in 2025, recruited 8,096 women aged 40 to 69; 5,509 could be classified by menopausal stage using STRAW+10. Moderate-to-severe vasomotor symptoms – hot flushes and night sweats – were particularly good at distinguishing perimenopause from premenopause. Vaginal dryness was also an important distinguishing symptom.

Crucially, women with regular cycles, changed flow and vasomotor symptoms reported a profile of similar severity to women in early perimenopause. However, this cross-sectional study relied on reported symptoms. It cannot establish sequence, prove causation or diagnose an individual. It supports closer attention to symptoms, but does not by itself rewrite current diagnostic criteria.

Further reading and scientific sources

• The Women Circle: how to tell whether you are in perimenopause or menopause
• PubMed: AMY study of symptoms across the menopause transition
• PubMed Central: clinical review of perimenopause, symptoms and treatment

Your step for this week

Take action: For seven days, spend two minutes recording your cycle or bleeding, hot flushes/night sweats, sleep and impact on daily life. At the end, look for a recurring pattern rather than perfect data.

Even with regular periods, your changes are real. Tracking brings clarity, and you can seek support early.