Ask anyone to name just one symptom of
Given the prevalence of hot flashes, you might be surprised to know how little we understand about this most common and disruptive of menopausal symptoms. While we understand some of the mechanisms behind them, their exact cause remains elusive. The latest studies suggest that these symptoms are the result of a complex series of hormonal interactions within the body that involve far more than just estrogen levels.
What We Know About Hot Flashes
The technical term for hot flashes (or hot flushes) is vasomotor symptoms, a term that simply refers to any movement that changes the diameter of the blood vessels in the body. Our bodies do this every day in response to signals from our external environment.
Our Internal “Thermostat” and Temperature Regulation
When it’s hot, for example, our core body temperature rises. To cool ourselves down, our hypothalamus — the thermostat for our bodies’ personal heating and cooling systems — signals our vessels to widen (or dilate) and thus allow more blood flow to the skin, where heat can dissipate more easily and cool us down.
The Anatomy of a Hot Flash
During menopause, however, hormonal changes trigger the thermostat into setting off false alarms, so that our blood vessels dilate and release heat even when our core temperature hasn’t changed. As a result, we flush with heat and sweat, primarily in the face, neck, and chest. Lasting, on average, about 1 to 5 minutes — though some can last as long as an hour — the intense heat of hot flashes is often followed by chills. While women experience hot flashes on average for 4 years during menopause, some women have them for as long as 20.
For more on how hot flashes happen, check out The Science Behind the Hot Flash (infographic).
What We Don’t Know (Yet) About Hot Flashes
What exactly causes these errors in body temperature regulation remains unknown. For a long time, scientists assumed the level of estrogen in our bodies was the sole determining factor.
Estrogen Does Not Act Alone
As women lost estrogen before, during, and after menopause, they would increasingly experience hot flashes. Surprisingly, however, further study showed that this wasn’t the case: women who experience hot flashes can have higher estrogen levels than women who don’t. Thus, estrogen plays a large role but does not act alone.
The KNDy, and Other Factors
More recent studies have provided some possible insights into other possible factors. A 2012 study out of the University of Arizona located a neuron, the KNDy (or “candy”), in the hypothalamus that is sensitive to estrogen levels and helps regulate body temperature.
Other studies suggest that elevated levels of the neurotransmitter norepinephrine narrow the normal temperature range in the hypothalamus, making our bodies react far more sensitively to small changes in core body temperature. Most likely, it’s a variety of factors individual to each woman that determine if, when, and for how long she experiences hot flashes.
Search for Effective Treatments Continue
“Within the next 25 years an estimated 1 billion women worldwide will be older than 50.”The Lancet
As a January 2017 article in the British medical
Hot flashes aren’t going away anytime soon, in other words, and searches for effective treatment will rely
Resources for Women
Hormone replacement therapy (HRT) is used to help reduce hot flashes. But it has risks. And it’s not a good option for women with a history of cancer or blood clots. Some women find herbal remedies to be effective at reducing the severity or frequency of menopausal symptoms. Here are a few guides to help you explore your options:
- Bioidentical Hormones and HRT for Women
- Supplements for Menopause: Five Key Vitamins and Nutrients
- Phytoestrogens: The Secret Ingredient in the Fight Against Hot Flashes
- Working Women and Menopause: Managing Your Symptoms in the Office
Sara A. Murphy is a freelance writer and editor with a PhD from Columbia University. She has written on a variety of topics, including health and fitness, travel, and social justice; she also edits both fiction and non-fiction. You can reach her at [email protected].