Lumia

Hot flashes and night sweats

5 min read Clinically reviewed · September 28, 2026 Updated: October 27, 2026 PerimenopauseMenopausePostmenopause

Summary

Hot flashes are the best-known symptom of the menopausal transition, affecting around three quarters of women. A sudden heat spreading from the chest to the face, sweating, sometimes palpitations, and then chills; it lasts a few minutes and can come several times a day or once an hour. The night-time version breaks up sleep. The average duration is longer than most women expect: it can exceed seven years. The most effective treatment for it is hormone therapy; for those who don't want hormones or can't take them, there are newer medicines and CBT. Which route is right for you is your doctor's decision.

What is happening?

Body temperature is held within a narrow "comfort range" in the hypothalamus. As estrogen fluctuates, the nerve cells that regulate that range (KNDy neurons) become overactive and the range narrows. The result: even a very small rise in body temperature is read as "overheating", and the body rushes to shed the heat — the skin's blood vessels widen (flushing, a feeling of heat), sweating starts, the heart speeds up. Once the heat is shed, chills follow. This reflex is triggered by the withdrawal of estrogen (both its fall and its fluctuation); symptoms begin in late perimenopause when estrogen is at its most erratic, are at their most intense in early postmenopause, and can continue for years after estrogen has settled at a permanently low level.

Triggers vary from person to person: a warm room, hot drinks, alcohol, spicy food, stress, smoking. The evidence that avoiding triggers reduces the symptom is weak, however; keeping a record is still useful for seeing your own pattern.

What do we know?

  • The duration is long: In the SWAN cohort, the median duration of frequent hot flashes was 7.4 years, and the median time they continued after the final period was 4.5 years. In women whose symptoms began early in perimenopause, the total duration was longer still (a median of more than 11 years) 1. In the Penn cohort, symptoms lasted ten years or more in about a third of women 2.
  • HRT is the most effective treatment: In a Cochrane review, estrogen-containing treatments reduced the frequency of hot flashes by around 75% compared with placebo 5. Guidelines position HRT as first-line for moderate-to-severe symptoms in suitable candidates 3.
  • Non-hormonal medicines are effective too: NK3 antagonists, certain SSRIs and SNRIs, gabapentin and oxybutynin have shown effectiveness in randomized trials; the size of the effect is generally smaller than with HRT but clinically meaningful 4. See the article on non-hormonal options for detail.
  • CBT reduces how problematic the symptom is: It reduces the distress it causes and its effect on sleep more than how often it happens; it is recommended by NICE 7.
  • Hot flashes are not merely an inconvenience: Frequent and severe vasomotor symptoms have been reported to be associated with cardiovascular risk markers and with white matter changes in the brain 6. Causation is not proven; but these findings are a further reason not to treat the symptom as "something to put up with".
  • Weight and smoking: Excess weight increases symptoms, and losing weight has been shown to reduce them. Hot flashes are more frequent and more severe in women who smoke 4.

What does this give you?

  • Record it, don't estimate it: A daily record of frequency and severity is the only concrete way to measure both the treatment decision and the response to treatment. In Lumia, mark hot flashes with the day/night distinction and with their severity.
  • "Waiting for it to pass" is an option, but not the only one: If symptoms are affecting your work, your sleep or your relationships, treatment is legitimate; "it's just your age" does not mean no treatment is needed.
  • For relief in the moment: Dressing in layers, a cool bedroom, breathable fabrics, slow breathing and cold water during an episode won't prevent the symptom, but they can make an episode easier to get through. The breathing tool in Lumia is there for this.
  • If night sweats are breaking up your sleep: see the sleep article; options that target night-time symptoms (gabapentin, HRT, CBT-I) can be discussed with your doctor.

When to see a doctor?

  • Hot flashes together with unexplained weight loss, constant palpitations, trembling hands, diarrhea, irritability — an overactive thyroid should be ruled out.
  • Night sweats together with fever, swollen lymph nodes, unexplained weight loss — infection and other causes should be assessed.
  • Sweating heavy enough to soak the bed at night only, with no hot flashes at all during the day — non-menopausal causes should be assessed.
  • Some medicines (certain antidepressants, tamoxifen, aromatase inhibitors, opioids) cause hot flashes; tell your doctor about symptoms that started with a new medicine.

These signs should be assessed without delay.

Sources

  1. Avis NE, et al. Duration of menopausal vasomotor symptoms over the menopause transition. JAMA Intern Med. 2015;175(4):531-539.
  2. Freeman EW, et al. Risk of long-term hot flashes after natural menopause. Menopause. 2014;21(9):924-932.
  3. The Menopause Society. The 2022 Hormone Therapy Position Statement. Menopause. 2022;29(7):767-794.
  4. The Menopause Society. The 2023 Nonhormone Therapy Position Statement. Menopause. 2023;30(6):573-590.
  5. MacLennan AH, et al. Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes. Cochrane Database Syst Rev. 2004;(4):CD002978.
  6. Thurston RC, et al. Menopausal vasomotor symptoms and white matter hyperintensities in midlife women. Neurology. 2023;100(2):e133-e141.
  7. NICE. Menopause: identification and management (NG23). 2015; updated November 2024.

What you can ask your doctor

  • Could my hot flashes be down to something else, such as my thyroid?
  • In my situation, which comes first: HRT, a non-hormonal option, or CBT?
  • How long might these symptoms last, and when will we review the treatment?

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This content is for information only; it does not replace medical advice, diagnosis or treatment. The choice of treatment is made only with your doctor. Lumia does not recommend medicines or doses.

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