Hot Flashes and Hot Flushes During Perimenopause and Menopause

Hot flashes are sudden feelings of intense warmth that spread across your body, usually concentrated in the face, neck, and chest. In many countries they are called hot flushes. Whatever you call them, they are the most widely recognised symptom of the menopause transition, and they affect roughly 75 to 80 percent of women.

If you are dealing with them, you are not imagining things. There is a clear biological explanation, and there are effective ways to manage them.

What Causes Hot Flashes

Hot flashes happen because of changes in the way your brain regulates body temperature.

During perimenopause, declining and fluctuating estrogen levels affect the hypothalamus, which is the part of the brain that acts as your internal thermostat. Research published in the Journal of Clinical Endocrinology and Metabolism has shown that reduced estrogen narrows the thermoneutral zone. That is the range of core body temperatures your brain considers normal. When this zone shrinks, even small increases in body temperature can trigger your brain to initiate rapid cooling through sweating, flushing, and increased heart rate.

A 2015 study from the University of Pennsylvania found that women with more frequent hot flashes showed greater activity in the brain's insular cortex, confirming that this is a neurological event rather than something purely vascular (Freedman, 2014).

How Common Are They

The Study of Women's Health Across the Nation (SWAN), one of the largest longitudinal studies of menopause involving over 3,000 women tracked since 1994, has produced some clear numbers:

About 80 percent of women experience hot flashes at some point during the menopause transition
They typically begin during perimenopause, often before periods stop entirely
The median total duration is 7.4 years, though this varies widely between women
Women who experience their first hot flash before their final period tend to have them for longer

The frequency varies considerably. Some women have a handful per week. Others report 10 or more per day.

When They Start and How Long They Last

Hot flashes can begin years before your last period. SWAN data published in JAMA Internal Medicine in 2015 found that:

Women who first experienced hot flashes while still menstruating had symptoms for an average of 11.8 years
Women whose hot flashes started after their periods stopped had symptoms for an average of 3.4 years
Black and Hispanic women tended to experience them for longer than white and Asian women

This means that the timing of onset matters. If yours started early in your perimenopause journey, you may want to discuss longer-term management with your doctor.

What They Feel Like

While experiences vary, most women describe a similar pattern:

A sudden wave of heat, usually starting in the chest or face
Flushing or visible reddening of the skin
Sweating, sometimes heavy
Increased heart rate or palpitations
A feeling of anxiety or unease during the episode
A chill afterwards as sweat evaporates

Individual episodes typically last between one and five minutes, though they can feel longer in the moment. When they happen at night, they are called night sweats and can be severe enough to soak through your bedding and seriously disrupt your sleep.

Common Triggers

Research has identified several triggers that can increase the frequency or intensity of hot flashes. Tracking yours alongside potential triggers can help you find your personal patterns.

Food and drink

Alcohol, particularly red wine
Caffeine
Spicy foods
Hot drinks

Environmental factors

Warm rooms or hot weather
Hot baths or showers
Heavy bedding or clothing in layers that trap heat

Other triggers

Stress and anxiety
Smoking. Research published in Obstetrics and Gynecology found that smokers experience more frequent and more severe hot flashes
Sedentary lifestyle

Many women find that once they identify their personal triggers, they can reduce the number of episodes they have. Tracking your symptoms daily is one of the simplest ways to spot these patterns.

What Helps: Evidence-Based Options

Hormone Therapy

Hormone replacement therapy (HRT) remains the most effective treatment. A Cochrane Review of 24 randomised controlled trials found that HRT reduces hot flash frequency by approximately 75 percent.

Both the North American Menopause Society and the American College of Obstetricians and Gynecologists confirm that HRT is safe and appropriate for most women under 60 or within 10 years of menopause onset. If you are considering this route, our complete guide to hormone therapy covers the research in detail.

Non-Hormonal Medications

For women who cannot or prefer not to use hormone therapy, several prescription options have shown effectiveness in clinical trials:

SSRIs and SNRIs such as paroxetine and venlafaxine can reduce hot flashes by 40 to 60 percent, according to research published in the Annals of Internal Medicine
Gabapentin has been shown to reduce frequency and severity, particularly for night-time episodes
Fezolinetant was approved by the FDA in 2023 as the first non-hormonal medication specifically designed for hot flashes. It works by targeting the neurokinin 3 receptor pathway in the brain

These are all worth discussing with your healthcare provider. Our article on talking to your doctor about perimenopause can help you prepare for that conversation.

Lifestyle Approaches

Cognitive Behavioural Therapy (CBT) A randomised controlled trial published in Menopause found that CBT significantly reduced the impact of hot flashes on daily life. While it did not reduce the number of episodes, it meaningfully changed how disruptive women found them.

Exercise The evidence here is mixed. A 2023 systematic review in Maturitas found that regular exercise may not directly reduce hot flash frequency, but it improves sleep quality, mood, and overall quality of life during the transition. That in itself makes it worth pursuing.

Keeping cool Practical strategies that many women find helpful day to day:

Dressing in layers that are easy to remove
Keeping a fan at your desk and bedside
Using cooling pillows or moisture-wicking bedding
Sipping cold water when you feel a flash starting

Supplements

Evidence for supplements is mixed. A systematic review in the Journal of Women's Health found that black cohosh has some evidence for mild relief, though results across studies are inconsistent. Phytoestrogens from soy and red clover show modest benefit in some trials. Many popular supplements lack strong clinical evidence. For a full breakdown, see our guide to supplements for perimenopause.

Always discuss supplements with your healthcare provider, as some can interact with medications.

The Connection to Other Symptoms

Hot flashes rarely happen in isolation. They are closely linked to several other perimenopause symptoms:

Sleep disruption: Night sweats are one of the leading causes of sleep problems during perimenopause
Fatigue: Poor sleep from night sweats contributes to daytime exhaustion
Mood changes: Sleep deprivation from night sweats can worsen anxiety and irritability
Brain fog: Research links disrupted sleep to the cognitive difficulties many women report

Addressing hot flashes often has a positive ripple effect on these related symptoms.

When to See Your Doctor

Talk to a healthcare provider about your hot flashes if:

They are regularly disrupting your sleep
They affect your ability to work or carry out daily activities
They are causing significant distress or anxiety
You are interested in exploring treatment options
They are accompanied by other symptoms that concern you, such as heart palpitations

Your doctor can help rule out other causes of flushing, such as thyroid conditions, and discuss treatment options suited to your specific situation.

Tracking Your Hot Flashes

Recording your hot flashes can reveal patterns you might not otherwise notice. Useful details to keep note of:

Time of day or night they occur
How long each one lasts
Severity on a simple scale
What you were doing, eating, or drinking beforehand
Whether anything seemed to trigger the episode

This information gives your doctor concrete data to work with when considering treatment, and it helps you take an active role in managing your symptoms. If you are not sure where you are in the menopause transition, our menopause stage assessment can help you get a clearer picture.

Sources:

Study of Women's Health Across the Nation (SWAN), National Institutes of Health
Avis, N.E. et al. (2015). Duration of Menopausal Vasomotor Symptoms Over the Menopause Transition. JAMA Internal Medicine, 175(4), 531-539
Freedman, R.R. (2014). Menopausal hot flashes: mechanisms, endocrinology, treatment. Journal of Steroid Biochemistry and Molecular Biology, 142, 115-120
The North American Menopause Society (2023). Nonhormone management of menopause-associated vasomotor symptoms: 2023 position statement
MacLennan, A.H. et al. (2004). Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes. Cochrane Database of Systematic Reviews