Your Brain on a Hot Flash

What causes menopausal hot flashes?

Alicia Scribner, M.D., associate professor of obstetrics and gynecology at the University of Washington School of Medicine, described a hot flash as a “sudden sensation of heat that begins centrally and spreads out.” One of her patients described it with more emotion: “She told me that when she gets a hot flash, she feels like her whole body is in flames,” Scribner said.

An individual hot flash can last five to six minutes. That may seem manageable, but women can have up to 20 hot flashes per day and they can continue for an average of seven years.

This leads to women everywhere asking: “Why is this happening to us? What is it about the menopause transition that causes our bodies to feel like they’re spontaneously combusting?”

Neurologists are closing in on the answer. The brain's ability to regulate temperature is closely tied to estrogen levels, said Kellyann Niotis, M.D., a New York City–based neurologist. When estrogen levels wobble during perimenopause then decline rapidly after menopause, the brain’s thermostat, the hypothalamus, is destabilized.

“When estrogen is no longer activating this region properly, the brain misreads internal temperature cues and triggers a cascade of events to cool the body down: widening blood vessels and starting sweat production,” she said.

There’s also evidence that dips in brain glucose levels contribute to menopausal hot flashes. “Estrogen normally helps maintain stable glucose delivery to the brain, so when levels fall, the brain may be more vulnerable to these dips — another trigger for hot flashes,” Niotis said.

A part of the brain called the prefrontal cortex, which governs stress reactivity and emotional regulation, may shape how disruptive or distressing hot flashes feel. In fact, said Niotis, “Women who are under more perceived stress or anxiety often report more frequent and more intense hot flashes even when objective physiological measures, like skin conductance, don’t differ. In other words, two women may have the same event, but the one under more emotional strain may experience it as more overwhelming.”

This may clarify how socioeconomic conditions and race factor into the hot flash equation. In the U.S., data show that Black women are more than twice as likely to experience frequent hot flashes compared to white women, and more likely to report them as more bothersome and disruptive to daily life and sleep. Hispanic women also report more frequent menopausal hot flashes than white women, though they tend to describe them as less intense and less disruptive.

If your life is being disrupted by your hot flashes, it’s time to seek treatment. “If women feel their symptoms are impacting their quality of life — their focus at work, fatigue, energy and sleep — it’s important to get help,” said Scribner.

Treatments for hot flashes

Although science has not yet found a cure for hot flashes, or a way to prevent them, there are plenty of medical and non-medical treatment options.

Hormone therapy (HT) works to control hot flashes and other menopause symptoms by replacing the estrogen lost to menopause. But for women who don’t want to take hormonal treatments or for those whose risk factors keep HT from being an option, there are non-hormonal treatments as well.

A class of drug called neurokinin receptor antagonists have been FDA-approved to treat moderate to severe menopausal hot flashes by addressing the chemical imbalance that can lead to hot flashes and night sweats. Other medication options include antidepressants. One antidepressant, paroxetine, has been FDA-approved to treat hot flashes, but other antidepressants are sometimes prescribed off-label, as are some anti-seizures medications, antispasmodics and blood pressure drugs.

The jury is out on herbal solutions, said Scribner. “I have heard from some of my patients that they're taking different herbs and supplements, but there’s no good data that supports the effectiveness of these,” said Scribner. However, believing something works — known as the placebo effect — can be helpful in reducing the perception of discomfort. As long as a solution isn’t harmful, Scribner said, “if you think something is making you feel better, you’ll get that benefit from it.”

Lifestyle changes can also help. “Caffeine, alcohol, hot drinks and spicy foods have been shown to trigger hot flashes,” Scribner said. But how much a person reacts to a potential trigger is highly personal. Scribner urged women to observe their personal hot flash patterns and make adjustments based on that insight. She also recommended sleeping in a cool room, and using a fan and ice packs at night.

When asked if hot flashes serve an evolutionary purpose that provide a benefit to menopausal women, Scribner laughed and said she was not aware of one.

But I have a (non-scientific) theory.

My friend, who has been experiencing hot flashes for over 10 years, improvised a solution one snowy night. Awake and sweating profusely, she crept outside and lay on the patio, pressing every part of her body into the stone to absorb every inch of soothing coolness into her flushed skin. Her husband, watching her from the window as she lay splayed on the patio in her nightshirt, said she must look crazy to the neighbors. “Not if the neighbors are in menopause,” she told him.

Maybe this — commiseration, empathy and commonality among menopausal women — is the purpose of the hot flash. Hot flashes give us the ability to observe our neighbor starfishing on her patio or watch our co-worker drop a bag of frozen peas into her bra, and think: “Aha! That’s clever.”

Hot flashes will never be cool, but they create a sisterhood of sweat for women in midlife.