Why hot flushes happen
Estradiol withdrawal sensitises the hypothalamic thermoregulatory centre, so it triggers heat-dumping (flushing, sweating) at the wrong moment. The trigger isn't 'low' estrogen as such — it's the fluctuation. That's why flushes often start in perimenopause when estradiol is still high on average.
When to test
Hot flushes plus changing cycles after 38 is almost always perimenopause — no test required to suspect it. A blood panel still helps: it confirms estradiol, FSH, progesterone and thyroid status, rules out hyperthyroidism (which also causes sweating and palpitations), and gives a baseline before HRT.
What actually works
Hormone replacement therapy (transdermal estradiol with progesterone if you have a uterus) is the most effective treatment — most women see 75%+ reduction within weeks. Non-hormonal options include SSRIs/SNRIs (paroxetine, venlafaxine), gabapentin, cognitive behavioural therapy for vasomotor symptoms, and the newer NK3-receptor antagonist fezolinetant where available.
Lifestyle levers worth using
Avoid identified triggers (alcohol, spicy food, caffeine, hot rooms), keep the bedroom cool, layer clothing, prioritise strength training (independent benefit on bone, body composition and sleep), and treat any sleep disorder. Don't replace medical treatment with these — stack them.
The 4–10 year hormonal transition before menopause — usually starts in the late 30s or 40s.
Frequently asked
Median duration is 7 years. About a third of women have them for 10+ years. They usually peak around the time of the final period.
Yes — flushes commonly start years before periods stop, while estradiol is still high but fluctuating wildly.
No — hyperthyroidism, certain medications, anxiety and (rarely) carcinoid syndrome can mimic them. A targeted blood panel rules these in or out.
For most women starting within 10 years of menopause and under 60, the benefits outweigh the risks. The decision is individualised — specialist input matters.
SSRIs/SNRIs at low dose, gabapentin, CBT for menopause symptoms, and (where available) fezolinetant. None match HRT for efficacy but all help where HRT isn't suitable.
Core body temperature naturally dips at night, so the threshold for triggering a flush is more easily crossed. Cooler bedroom (16–18°C) and breathable bedding meaningfully reduce them.