Your periods have gone rogue. You can’t sleep. You keep losing your train of thought mid-sentence — and nobody, not your GP, not Google, not your friends, has given you a satisfying explanation. What if every single one of those things has one name?

Watch first: 10 signs you’re already in perimenopause — and you had no idea

What is perimenopause — and why does everyone miss it?

Perimenopause means “around menopause.” It’s the transition phase before your final period, when hormone levels — particularly oestrogen and progesterone — begin to fluctuate. That fluctuation is what causes your symptoms.

Actual menopause is confirmed 12 months after your last period. But perimenopause can start years before — sometimes as early as 35.

It is the condition most missed and most mistaken for something else in women’s health. If you’re in your late thirties or forties and something feels off, this post is for you.

The 10 signs to know

1. Your period has become unpredictable

Shorter. Longer. Heavier. Lighter. Disappearing for a month and then reappearing. Fluctuating oestrogen affects both ovulation and your womb lining — which is why your cycle stops making sense.

Track your cycle for at least three months and bring that log to your GP appointment.

⚠️ Very heavy bleeding, flooding, passing clots, or soaking through a pad in an hour needs a separate assessment to rule out fibroids or other endometrial changes. Irregular doesn’t always mean just hormones — please get it checked.

2. Hot flushes and night sweats

That sudden wave of heat across your face, neck, and chest — sometimes followed by chills. Waking up drenched at 2am. Fluctuating oestrogen tricks your brain’s thermostat (the hypothalamus) into registering a false temperature spike, and your body scrambles to cool itself down.

⚠️ If night sweats come with unexplained weight loss, persistent fever, or lumps anywhere in your body — please see your GP urgently. These need investigating before hormones are assumed to be the cause.

3. Sleep disturbances

Can’t fall asleep. Waking at 3am with a racing mind. Progesterone has a natural sedating effect on the brain. As levels drop, sleep patterns shift. This is not you getting older — this is hormonal.

Poor sleep amplifies every other symptom on this list. If it’s affecting your daily functioning, that’s a conversation worth having with your GP.

4. Brain fog and memory issues

That “tip of the tongue” moment that never resolves. Words hanging mid-sentence. Walking into a room and forgetting why. Oestrogen plays a direct role in memory and cognitive sharpness — when it fluctuates, so does your clarity.

Perimenopausal brain fog is a real, scientifically recognised phenomenon. It improves as hormones stabilise.

⚠️ If memory loss feels more significant than forgetting words — that warrants a separate assessment. Mention it to your GP, especially if it started alongside other symptoms on this list.

5. Mood changes — anxiety, low mood, irritability

Anxiety. Weeping without a clear reason. Snapping at people you love and feeling awful about it. “Just not feeling like yourself.”

Oestrogen regulates serotonin — the brain chemical that helps stabilise mood. When oestrogen fluctuates, so does your ability to regulate emotions. This is a biochemical issue, not a character flaw.

Many women are diagnosed with depression during perimenopause when the underlying cause is hormonal. If your mood shifted in your late thirties or early forties without a clear life trigger — mention perimenopause specifically to your GP. Don’t wait for them to bring it up first.

6. Heart palpitations

A racing, fluttering, or skipping sensation in your chest — often at rest or at night. Normal oestrogen levels help keep heart rhythm stable. When those levels fluctuate, some women experience brief, benign palpitation episodes.

⚠️ If palpitations are persistent, or come with chest pain, shortness of breath, or feeling faint — this is A&E territory, not a watch-and-wait situation. Heart causes must be ruled out first.

7. Joint pain and muscle aches

Aching knees, hips, back, hands, wrists — out of nowhere. Oestrogen has anti-inflammatory properties. As levels drop, inflammation in your joints can develop or increase.

This is one of the most overlooked perimenopause symptoms. Many women are referred to rheumatology before anyone considers hormones. If you’re in your forties with new joint pain and other symptoms from this list — connect those dots in your next appointment.

8. Vaginal dryness and changes in libido

Dryness, discomfort during sex, reduced natural lubrication, and a significant drop in sexual desire. Your vaginal and vulval tissues rely on oestrogen. As levels drop, these tissues become thinner and less moist — a condition called the Genitourinary Syndrome of Menopause (GSM), affecting around 50% of women in the menopause transition.

This is not something you need to put up with. Vaginal moisturisers used 2–3 times a week can help with day-to-day comfort. Your GP can also discuss further treatment options with you.

9. Skin and hair changes

Skin feeling thinner, drier, less elastic. Hair getting finer or shedding more than usual. Oestrogen stimulates collagen production and supports hair follicle growth — both decline as oestrogen fluctuates.

An underactive thyroid can coexist with perimenopause and cause nearly identical changes. If you’re noticing significant hair or skin changes, ask your GP for a hormone profile and a thyroid profile at the same appointment.

10. Weight gain around your middle

Gaining weight around your belly even though your diet hasn’t changed. Two things happen:

1. Fat distribution shifts from hips and thighs to the abdomen.
2. Your body’s sensitivity to insulin changes — it processes carbohydrates less efficiently. This is called insulin resistance.

This is not a willpower problem. It is a metabolic shift.

Research supports strength training (even twice a week) and reducing processed and refined carbohydrates. Ask your GP to check your fasting glucose and HbA1c if you notice this change alongside other symptoms.

Download the free Menopause & Midlife Health Guide — know your symptoms, know your options, and go to your GP fully prepared

When to see your GP — urgency guide

The bottom line

Perimenopause can start as early as 35 and last for four to ten years — which means many women are living inside it long before anyone gives it a name. If you recognise yourself in three or more of these signs, that is not a reason to panic. It’s a reason to act. Go to your GP with a three-month symptom log, name perimenopause directly, and ask for a full hormone and thyroid profile. You have every right to a clear answer.

Which of these signs stopped you in your tracks? You’re not alone in this — come and share it with us. → Join the free AskAwayHealth Substack for fortnightly health tips.

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• Why Perimenopause Is The MOST Important Time of Your Life
• 10 Signs You’re Already in Perimenopause — And What to Do Next
• Perimenopause Symptoms Nobody Warns You About
• Say Goodbye to Menopause Joint Aches: Natural Remedies and Lifestyle Changes

Medical disclaimer: This post is for educational purposes only and does not constitute medical advice. Reading this content does not create a doctor-patient relationship with Dr Sylvia or AskAwayHealth. Always consult your own GP or healthcare provider about your individual circumstances. If you are experiencing a medical emergency, call 999 or attend your nearest A&E.