Here's something most people get wrong: menopause is not the years-long experience most of us picture.

Menopause itself is a single point in time: the moment you've gone 12 consecutive months without a period. But what leads up to it, called perimenopause, is a transition that can begin in a woman's mid-30s and typically starts in her 40s, lasting anywhere from a few years to over a decade. During this time, the ovaries gradually produce less estrogen and progesterone, the two hormones that regulate the menstrual cycle. (Cleveland Clinic, Johns Hopkins Medicine)

The key detail most people miss: these hormone levels do not decline smoothly. They fluctuate, rising and falling unevenly, sometimes within the same week. That instability, not a steady drop, is what drives most of the symptoms associated with this stage.

Menopause itself is reached after 12 consecutive months without a period, typically in a woman's early 50s, though the average age varies across racial and ethnic groups and individual factors.

When menopause arrives earlier than expected

This timeline assumes a natural transition, but not everyone arrives at menopause this way. A hysterectomy, particularly one that includes removal of the ovaries, can bring on menopause immediately, regardless of age. This is known as surgical menopause, and unlike the gradual hormone decline of a natural transition, it causes an abrupt drop in estrogen that often produces more intense symptoms. (Cleveland Clinic) Even when the ovaries are left intact, a hysterectomy alone is associated with reaching menopause several years earlier than women who have not had the surgery, likely due to changes in blood flow to the ovaries. (PubMed, Hysterectomy and Menopause Cohort Study) Cancer treatments like chemotherapy and radiation can have a similar effect, bringing on menopause earlier than it would have occurred naturally.

This matters because so many women going through surgical or treatment-induced menopause do not realize what is happening to their bodies until well after symptoms begin. The timeline looks different, but the underlying hormonal shift is the same.

Why the symptoms reach so far beyond hot flashes

Estrogen does far more in the body than regulate the reproductive cycle. It plays a role in metabolism, bone density, cardiovascular health, skin elasticity, and brain function. That is part of why the symptoms of perimenopause show up in so many seemingly unrelated places.

When estrogen fluctuates, the body's insulin regulation and fat distribution can shift, which is why some women notice metabolic changes during this stage that have nothing to do with diet or exercise habits changing. (Estrogen and Metabolism Review, PMC) Estrogen is also closely linked to serotonin, which helps explain why mood changes, anxiety, and irritability are so common during perimenopause despite having nothing to do with someone's personality or circumstances.

Cognitive changes are real too, not imagined or exaggerated. Research using brain imaging has found altered activity in regions tied to memory and cognitive function in women going through this transition, correlating directly with estrogen levels. The brain fog many women describe has a measurable biological basis. (Altered Spontaneous Brain Activity Study, PMC)

Why so few people understand it

If the biology is this well understood by researchers, why does it still feel like a mystery to so many people living through it?

Part of the answer is generational. Many of us grew up in homes where women's reproductive health was treated as something private at best and shameful at worst. Our co-founder Nazanin put it this way: "I grew up in a culture where topics related to women's reproductive health were rarely discussed openly. The intention was probably to protect children, preserve privacy, or avoid uncomfortable conversations. But for me, that silence created fear where understanding could have existed."

But there is a structural reason too, and it starts inside medical training itself. A 2023 survey of OB-GYN residency program directors found that only 31.3% of programs had a dedicated menopause curriculum, even though nearly all of the directors surveyed agreed residents nationwide should have one. (Healio) Separate research found that just 6.8% of family medicine, internal medicine, and OB-GYN residents felt adequately prepared to manage patients going through menopause, and one in five reported receiving no menopause education at all during their residency. (The Flow Space) At many medical schools, the entirety of menopause education amounts to a single one-hour lecture, if it is taught at all.

This is not a uniquely American problem. A UK-based survey found that menopause education was not part of the mandatory curriculum at 41% of medical schools surveyed. (ScienceDirect)

The research gap runs even deeper than the education gap. Women were not required to be included in clinical trials in the United States until 1993, and as recently as 2018, only 15% of the National Institutes of Health's research budget was allocated to women's health. (Davis Wright Tremaine) A 2025 analysis found that conditions like menopause, PMS, and endometriosis make up 14% of the overall health burden women carry, yet received less than 1% of research funding directed toward closing the women's health gap between 2019 and 2023. (World Economic Forum)

Put plainly: the doctors most women rely on were rarely trained on this, and the research base they would otherwise draw from has been historically underfunded and underbuilt. That inherited silence compounds the medical gap. Even women who try to start the conversation with a doctor do not always get clear answers, not necessarily because their provider does not care, but because the system never gave them the training or the evidence base to draw from. The result is a transition that affects roughly half the population at some point in their lives, and yet remains one of the least understood and least resourced experiences in healthcare.

Understanding is the first step toward support

The biology behind this has been studied for decades. What's been missing is the willingness to talk about it, at home, at work, and everywhere in between.

If you want to start that conversation at home, the Menopause Foundation of Canada's guide on supporting a partner through menopause is a practical place to start. In the US, HealthyWomen's guide on how partners can support women through menopause covers similar ground. And if you are thinking about this at an organizational level, we wrote about why workplaces need to normalize this conversation and what employers can actually do about it.