Hot flashes are sudden surges of heat that spread through the upper body, typically accompanied by sweating, skin flushing, and sometimes chills. They are the most common symptom of menopause, affecting roughly 85% of women during the menopausal transition. Most last between one and five minutes, though some can stretch much longer. In one U.S. study, 87% of women with hot flashes reported having them daily, and about a third experienced more than 10 per day.
What a Hot Flash Feels Like
The sensation typically starts as a wave of intense warmth rising through the chest, neck, and face. Sweating concentrates in those same areas. Some women flush visibly, turning red across the chest and cheeks. As the episode fades, a chill often follows as the body overcorrects its temperature. Heart rate can spike during a flash, and many women describe a sense of anxiety or unease that comes on with the heat and passes just as quickly.
About 55% of women begin experiencing hot flashes during perimenopause, the transition period when menstrual cycles start becoming irregular. For some women, hot flashes continue for a few years around menopause. For others, they persist for a decade or more.
Why They Happen
Hot flashes are driven by changes in the brain’s internal thermostat. As estrogen levels drop during menopause, a group of nerve cells in the hypothalamus becomes overactive. These neurons normally help regulate body temperature, but without estrogen keeping them in check, they fire too easily, essentially telling the body it’s overheating when it isn’t. The brain then triggers its standard cooling response: blood vessels near the skin dilate to release heat, sweat glands activate, and you feel that characteristic flush.
A signaling molecule called neurokinin B plays a central role in this process. When researchers administered neurokinin B to healthy women, it reliably triggered hot flashes with measurable increases in skin temperature. Blocking its receptor reduced hot flash symptoms significantly, which is the basis for one of the newer treatments.
Night Sweats Are Not the Same Thing
Night sweats and daytime hot flashes are often lumped together, but recent research suggests they are distinct phenomena. In objective measurements, night sweats lasted an average of about 60 minutes compared to roughly 3.4 minutes for daytime hot flashes. Women who experience both describe night sweats as prolonged, full-body sweating events that often lack the intense burst of heat or anxiety typical of a daytime flash. Night sweats tend to occur earlier in the sleep cycle and can severely disrupt sleep quality, compounding fatigue, mood changes, and difficulty concentrating during the day.
Causes Beyond Menopause
While menopause is by far the most common cause, hot flashes can be triggered by other conditions and medications. Hyperthyroidism, certain rare tumors (carcinoid tumors, pheochromocytoma), and systemic allergic reactions can all produce similar symptoms.
Several medications are known to cause hot flashes as a side effect. Tamoxifen, widely used in breast cancer treatment, causes hot flashes in up to 80% of women taking it. Certain antidepressants, including tricyclics and some SSRIs, can trigger them as well. Chemotherapy drugs, fertility medications like clomiphene, and some blood pressure medications (calcium channel blockers) are also on the list. If you’re experiencing hot flashes and aren’t near menopausal age, medications or an underlying condition may be the cause.
Common Triggers
Even when the underlying cause is hormonal, certain everyday factors can set off individual episodes or make them worse. Spicy foods are among the most commonly reported triggers. Alcohol increases both the frequency and intensity of hot flashes. Hot beverages, caffeine, warm environments, stress, and tight clothing can also provoke episodes. Many women find that identifying and avoiding their personal triggers meaningfully reduces how often hot flashes occur.
Links to Cardiovascular Health
Hot flashes may be more than a nuisance. A study from the Study of Women’s Health Across the Nation found that women with hot flashes showed reduced blood vessel function and greater calcium buildup in their aorta and coronary arteries, both markers of early cardiovascular disease. These associations held even after accounting for traditional heart disease risk factors and estrogen levels. The same vascular markers are prospectively linked to stroke, coronary heart disease, and cardiovascular death. This doesn’t mean hot flashes cause heart disease, but it suggests that women who experience frequent or severe hot flashes may benefit from paying closer attention to their cardiovascular health.
Prevalence Varies Globally
How common hot flashes are depends partly on where you live. Studies show Turkish women report the highest rates at 97%, followed by Australian women at 83%, European women at 76.5%, and North American women at about 59%. Women in South America (47%) and Asia (45%) report lower rates. These differences likely reflect a combination of genetics, diet (particularly soy intake in Asian populations), body composition, and cultural factors in how symptoms are reported.
Treatment Options
Hormone Therapy
Estrogen therapy remains the most effective treatment for hot flashes. It works by restoring the hormonal signal that keeps the brain’s thermostat functioning normally. Hormone therapy comes in pills, patches, gels, and sprays, and the choice depends on your health profile and preferences. It’s not appropriate for everyone, particularly women with a history of certain cancers, blood clots, or liver disease.
Non-Hormonal Medications
For women who can’t or prefer not to take hormones, several non-hormonal options exist. Fezolinetant (Veozah), approved by the FDA in 2023, works by blocking the neurokinin B receptor directly involved in triggering hot flashes. It’s taken as a once-daily pill. One important note for women taking tamoxifen: certain SSRIs, particularly paroxetine, interfere with how the body processes tamoxifen and should be avoided. SNRIs like venlafaxine are a better option in that situation.
Herbal and Dietary Approaches
Black cohosh is the most widely studied herbal remedy for hot flashes. Compounds in its root interact with estrogen receptors and suppress certain hormonal signals without producing permanent estrogen-like effects. It has been used for years to treat hot flashes, night sweats, insomnia, and irritability, with no dangerous side effects reported at standard doses. Soy isoflavones and red clover have also shown some effectiveness in managing menopausal symptoms, though the evidence for these is less robust. The variation in hot flash rates across countries with different soy consumption patterns is suggestive but not conclusive.