According to the North American Menopause Society, as many as 75% of North American women have hot flashes during perimenopause. How often these episodes happen can vary from person to person. A woman in the menopause transition, who is not on birth control or hormone replacement therapy, will experience hot flashes, on average, four to five times a day — but Barbieri says some people experience them less than that, and sometimes people have far more (up to 20 a day).
So why does this happen as you get closer to menopause? According to Schroeder, doctors aren’t 100% sure, but they do have some theories. Estrogen starts to drop significantly as you approach menopause, and this appears to have an effect on your hypothalamus, the part of your brain that’s responsible for regulating your body temperature.
“When estrogen goes down, it removes a brake on the hypothalamus, and we think it starts to fire irregularly and doesn’t interpret the temperature signals in a stable way,” says Barbieri. In other words, your body mistakenly starts to think you’re overheating, so you start sweating to keep you from getting too hot.
Hot flashes can happen for other, non-menopause reasons too. Barbieri says you might notice feeling hotter just before your period (when estrogen naturally starts to dip). And if you take birth control, you might have a hot flash when you take the placebo sugar pills because your estrogen levels are falling rapidly. Thyroid conditions and (rarely) certain cancers can cause hot flashes, and you can also experience them when you have an infection. An anxiety attack can also cause sudden flushing and sweating but those symptoms are usually accompanied by an increased heart rate and shortness of breath, which you won’t experience with a hormone-driven hot flash.
How to tell if your hot flash could be related to menopause
Most of the time, Barbieri says, persistent hot flashes are associated with changes in estrogen leading up to menopause. But if you’re not totally sure, a few key factors can help you determine whether your hot flashes might be tied to menopause — and prompt you to reach out to your medical provider for support if needed.
You’re in your forties
Your age is one of the most important clues that your hot flashes are associated with menopause. While certain factors, like smoking or chemotherapy, could cause your estrogen levels to start dipping sooner, according to Schroeder, most people start to notice menopause-related symptoms in their early- to mid-forties. So if you’re 25 and you have one hot flash, menopause is unlikely. Schroeder says the age menopause happens to you is genetically predetermined, so it could be worth checking in with your older relatives who’ve been through menopause to see when it happened for them.
Your period is changing
By definition, menopause is when you stop getting periods (because you’ve stopped ovulating). Perimenopause is the process leading up to that, and Barbieri says it can last around a decade. During that time, you’ll definitely see changes in your menstrual cycle. Your cycle could be erratic and unpredictable if your estrogen levels are on the decline, Barbieri says. You might also skip the bleeding phase altogether if you’re inching closer to life without a period.
The episodes are persistent
If you have one hot flash, or it only happens before your period, don’t be quick to assume you’re approaching menopause. When your estrogen declines, you’ll likely notice persistent symptoms that get more intense over time.