Affecting up to 85% of women aged 45 and older, hot flashes are one of the most common symptoms of menopause and perimenopause. Disrupting your day (or night), they can occur at any time, causing a sudden wave of heat, sweating, flushing, and often, a racing heart.
“Hot flashes are far more than just a momentary discomfort; they are a deeply personal and often disruptive signal of significant hormonal shifts within a woman’s body. Like many facets of a woman’s journey through perimenopause, they’re too often dismissed or misunderstood,” explains Dr. Neta Gotlieb, PhD, Senior Product Manager, Women’s Health, at Oura.
Keep reading to understand what causes hot flashes, what happens in your body during a hot flash, and what you can do to reduce the severity and frequency of hot flashes.
READ MORE: How Oura Can Help You Manage Perimenopause
What Are Hot Flashes?
When people talk about hot flashes, they’re usually referring to the menopause and perimenopause symptom, though men can experience hot flashes as well. A hot flash typically manifests as a sudden feeling of intense warmth, most noticeably across the face, neck, and chest. Along with flushed skin, it’s common to experience a rapid heartbeat, sweating, dizziness, and anxiety, sometimes followed by a chill as your body cools down.
A hot flash episode typically lasts between one and five minutes, though the duration and intensity can vary widely from person to person. When they occur at night (often called night sweats), they can wake you up and disrupt your sleep, leaving you feeling foggy and fatigued the next day.
As noted, they’re a highly common occurrence among women going through perimenopause. This is supported by de-identified data from Oura Members showing that women aged 45 to 54 are 57% more likely to tag “hot flashes.”
LEARN MORE: How Menopause Impacts Sleep
What Happens in Your Body During a Hot Flash
Hot flashes are primarily triggered by hormonal shifts—most notably, the natural decline in estrogen that occurs during perimenopause and menopause.
Estrogen helps regulate your body’s temperature trends, which are controlled by the hypothalamus, a region in the brain. As estrogen levels drop, this internal “thermostat” becomes hypersensitive to even minor temperature changes, narrowing what’s known as your thermoneutral zone—the range of temperatures at which you don’t sweat or shiver.
As a result, even a slight rise in core temperature can trigger the body’s full heat-dissipation response, in which your blood vessels dilate, you begin to sweat, and your heart rate rises to cool you down.
During a hot flash, the central sympathetic nervous system also becomes more active, as indicated by elevated activity levels. This heightened activation further reduces the body’s thermoneutral zone, increasing susceptibility to hot flashes.
Beyond thermoregulation, estrogen also plays a key role in modulating the body’s stress response and maintaining vascular stability. As estrogen levels decline during menopause, the hypothalamic-pituitary-adrenal (HPA) axis, which is responsible for the stress response, becomes more easily activated.
This increased reactivity can lead to higher levels of cortisol and adrenaline, which in turn activate the sympathetic nervous system and mimic the same physiological changes seen in a hot flash—such as flushing, sweating, and an increased heart rate.
8 Potential Triggers of Hot Flashes
1. Alcohol and Caffeine
These substances act as vasodilators, expanding blood vessels and increasing blood flow to the skin, which can make you feel flushed and sweaty. Caffeine also stimulates the central nervous system, increasing heart rate and potentially activating the same sympathetic pathways that contribute to hot flashes.
| Member Tip: Tag alcohol, caffeine, and other habits in the Oura App as well as hot flashes to track how each choice impacts their occurrence. |
2. Spicy Foods
Hot, spicy foods contain compounds like capsaicin that can stimulate nerve endings and create a sensation of heat throughout the body.
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3. Stress and Anxiety
Certain triggers, like public speaking or an argument with a spouse, can increase the likelihood of a hot flash. Both acute stress and chronic anxiety stimulate the HPA axis, releasing stress hormones like cortisol and adrenaline. This response can narrow the thermoneutral zone and cause heat-dissipation responses such as sweating, flushing, and increased heart rate.
READ MORE: 9 Simple (and Science-Backed!) Ways to Lower Stress
4. Warm Rooms or Hot Weather
Environmental heat can raise your core body temperature and trigger hot flash-like symptoms, especially during sleep. A 2024 study published in Menopause found that acute increases in temperature were significantly associated with the odds of subjectively reported nighttime hot flashes.
This means that even small increases in room temperature can push your body outside its thermoneutral zone, activating heat-dissipation responses like flushing, sweating, and restlessness.
5. Sudden or Intense Exercise
Exercise can be both a treatment and a trigger for hot flashes. Regular, moderate-intensity exercise has been shown to reduce the frequency and intensity of hot flashes over time. However, sudden spikes in physical activity, especially when the intensity is higher than what your body is used to, can do the opposite.
One 2024 study found that acute increases in physical activity significantly raised the odds of both objectively and subjectively measured hot flashes in menopausal women during waking and sleeping hours.
6. Strong Emotions
It’s not just stress and anxiety that can trigger a hot flash—research shows that even positive emotions can. A 2005 study found that hot flashes were more likely after increased happiness, relaxation, and feelings of control. This is believed to be due to autonomic arousal or changes in core temperature.
READ MORE: How Anxiety Affects the Brain—Plus 3 Science-Backed Ways to Manage It
7. Smoking
Cigarette smoking significantly increases the risk of hot flashes—both former and current smokers are more likely to experience them compared to those who’ve never smoked.
A study showed a dose-response relationship, meaning the risk increased with both the number of cigarettes smoked and the duration of smoking. However, women who quit before age 40 had a similar risk level as never-smokers, highlighting the benefits of early cessation.
8. Higher Body Mass Index (BMI)
Higher body weight may heighten the frequency and severity of hot flashes. A pooled analysis of 21,000 women found that those with a higher BMI were significantly more likely to experience frequent or severe vasomotor symptoms, such as hot flashes and night sweats. The relationship was dose-dependent, meaning the greater the BMI, the higher the likelihood and severity of symptoms.
How to Reduce the Frequency or Severity of Hot Flashes
While you can’t always prevent a hot flash, you can take steps to reduce their frequency and manage their impact. Here are some strategies that can help.
1. Track Your Triggers With Oura
Use Tags in the Oura App to note when hot flashes occur and what might have preceded them—such as stress, a specific food or drink, or poor sleep. Over time, patterns may emerge.
Identifying your personal triggers allows you to make targeted lifestyle changes that could reduce hot flash intensity or frequency.
2. Speak to Your Doctor About Menopausal Hormone Therapy
Menopausal hormone therapy (MHT) is the most effective treatment available for hot flashes. That’s because it directly addresses the root cause: declining estrogen levels. By restoring estrogen to more stable levels, MHT helps recalibrate your body’s internal thermostat, reducing the frequency, intensity, and unpredictability of hot flashes.
So if hot flashes are disrupting your sleep, mood, or daily life, talk to your healthcare provider to explore whether MHT is a suitable option for you.
| Member Spotlight: Saša M., 45, used Oura’s Cycle Insights to notice that her cycle was becoming longer and more irregular. With her doctor’s guidance, she tried menopausal hormone therapy to manage her symptoms. |
3. Switch Up Your Sleep Environment
Hot flashes can seriously disrupt your sleep, especially during the luteal phase or perimenopause. A warm bedroom or heat-trapping sleepwear can make symptoms worse. Cool it down by adjusting your room temperature, wearing moisture-wicking pajamas, and avoiding heavy meals or alcohol before bed.
4. Practice Stress Reduction Techniques
Hot flashes are more common during moments of anxiety or emotional arousal, so calming the nervous system may reduce their intensity. Try breathwork, meditation, reading, journaling, creating a calming environment, and other stress management techniques to reduce sympathetic nervous system activation.
LEARN MORE: 10 Simple Breathing Exercises for Sleep and Relaxation
Oura Member Julie D., age 56, is an Ironman athlete who turns to her Oura Scores to regulate her training levels.
5. Exercise Regularly
Despite the findings that sudden or intense exercise can increase hot flashes, research shows that regular, moderate-intensity exercise has been consistently associated with fewer and less severe hot flashes over time. It also improves sleep, mood, and stress resilience—all of which can help reduce vasomotor symptoms.
6. Consider Nutrition and Hydration
Stay hydrated and limit potential dietary triggers like caffeine, alcohol, and spicy foods. Some research suggests that foods rich in phytoestrogens—such as soy, flaxseeds, and legumes—may support estrogen balance, though individual responses vary.
How to Find Relief During a Hot Flash
Hot flashes can strike unexpectedly, but having a plan can help you stay calm and comfortable. Below, find five strategies to ease the intensity and duration of a hot flash.
- Pause and breathe: When a hot flash begins, stop what you’re doing and take slow, deep breaths. Deep breathing can activate your parasympathetic nervous system, helping to reduce the severity of the episode.
- Sip cold water: Drinking a glass of cold water can help lower your core body temperature from the inside, providing relief during a hot flash.
- Dress in layers: Wear lightweight, breathable clothing in layers so you can easily remove items as needed to cool down. Natural fibers like cotton are ideal.
- Use cooling tools: Keep a portable fan, cooling towel, or cold pack accessible to turn to when a hot flash hits. These can help dissipate heat quickly.
- Distract yourself: It can feel overwhelming when you start to feel your temperature randomly rise. Try to redirect your attention with something calming or enjoyable.
RELATED: 10 Simple Breathing Exercises for Sleep and Relaxation