Menopause is one day, and the age it arrives shapes your heart and bones

Key takeaways

• A 2024 international guideline says about 3.5% of women lose ovarian function before 40 for reasons other than medical treatment, a condition called premature ovarian insufficiency, compared with about 1% in older studies¹.
• In a British study of 144,260 women, 6.0% of those whose menopause came naturally before 40 developed cardiovascular disease over about seven years, compared with 3.9% of women whose menopause came at 40 or later³.
• In a large U.S. study, LDL cholesterol and apoB rose sharply from the year before the final period to the year after, a jump tied to menopause rather than age alone⁶.
• Within a decade of menopause, some women lose as much as a quarter of their bone mass, according to the federal Office on Women’s Health⁹.
• Women learned less from repeated memory tests during perimenopause, but the dip disappeared after menopause¹¹.

Older studies found that about 1 woman in 100 loses ovarian function before 40¹. A 2024 guideline from three international medical societies and an Australian research center puts the share much higher¹.

Pooling recent studies, the guideline puts this early loss of ovarian function, when medical treatment isn’t the cause, at about 3.5% of women¹. By our math, that’s roughly 1 in 29. Add early menopause, in the early 40s, and the guideline calls the combined picture quite common¹.

Timing matters because of what comes next. In 2019, researchers writing in JAMA followed 144,260 women in the UK Biobank, a large British health study, for a median of seven years³.

Among women whose menopause came at 40 or later, 3.9% developed cardiovascular disease, the family of heart and blood vessel conditions³. That rose to 6.0% after natural menopause before 40 and 7.6% after both ovaries were removed before 40³. By our math, that’s about 21 and 37 extra cases per 1,000 women.

Menopause itself is a single day on the calendar. But the changes around it, in cholesterol, arteries, bone and even learning, play out for years. This guide covers what changes, why early and surgical menopause deserve special attention, how experiences differ, and what to check.

Menopause is a date you only know in hindsight

Menopause is confirmed once you’ve gone 12 months in a row without a period, not even spotting⁴. In the U.S., the average age is 52⁴. Worldwide, the average falls between 48 and 51².

Most women reach it naturally, as the ovaries wind down. Surgery that removes both ovaries starts menopause right away⁴. Chemotherapy and pelvic radiation can also bring it on early⁵.

The hormone shift starts well before the last period. Long-term studies found estradiol falling as early as two years before the final period⁶. One of them is the Study of Women’s Health Across the Nation (SWAN), a long-running American study of midlife women. FSH, a pituitary hormone that pushes the ovaries, began rising about six years before⁶.

To the National Institute on Aging, menopause is ordinary aging rather than an illness¹⁵. That fits a natural-health view of the body. Normal still has health consequences, and knowing them lets you act early with the habits you already value.

Early menopause is more common than once thought

Guidelines use two cutoffs. Menopause before 40 is premature menopause, and menopause from 40 to 44 is early menopause⁵. OWH also calls the first one primary ovarian insufficiency, while the 2024 guideline says premature ovarian insufficiency; both shorten to POI¹⁵.

Sometimes no cause turns up. Known causes include a family history of early menopause, smoking, cancer treatment, autoimmune conditions such as thyroid disease, and genetic conditions such as Turner syndrome⁵. OWH advises reporting periods that stop or turn irregular before 45⁵.

The 2024 POI guideline, from ESHRE, the American Society for Reproductive Medicine, the International Menopause Society and an Australian research center, simplified diagnosis. It now takes at least four months of absent or irregular periods plus one FSH result above 25 IU/L; the 2015 version required two¹.

The health stakes are real. The guideline links POI to lower bone density, heart disease, heart failure and stroke, and a higher risk of cognitive decline and dementia¹. Without hormone therapy, it says, POI is tied to shorter life expectancy, mostly from cardiovascular disease¹.

So the guideline recommends hormone therapy for women with POI until they reach the typical age of natural menopause, to help prevent those problems whether or not they have symptoms¹. It’s generally not recommended for women who’ve had breast cancer¹. The Menopause Society’s 2022 position statement takes a similar line for premature and early menopause: it supports hormone therapy until at least the average age of natural menopause, unless there’s a medical reason to avoid it⁸.

The guideline also calls for a bone density scan at diagnosis, a yearly check of blood pressure, weight and smoking, and cholesterol and diabetes tests at diagnosis¹. It encourages not smoking, a healthy diet and regular activity to protect the heart¹.

The news can hit hard. OWH notes that a diagnosis can bring grief, especially about fertility, and that counseling and support groups help⁵. Natural conception is much less likely with POI but not impossible¹. Women who have lived with POI advised the guideline team on how clinicians should break the news, and the team says it should be done with care².

Removing the ovaries early carries its own risks

Surgical menopause is the most abrupt kind. In 2020, an American Heart Association (AHA) scientific statement summed up earlier research. Removing both ovaries before about 40 to 45 sharply raised the risk of coronary heart disease, it said⁶. Surgery near the age of natural menopause showed little or no link, and hysterectomy that leaves the ovaries wasn’t tied to higher heart risk⁶.

The Mayo Clinic Cohort Study of Oophorectomy and Aging followed women in Olmsted County, Minnesota, who had surgery from 1950 to 1987⁷. Women who had both ovaries removed before 45 had a higher death rate over the following decades, about two-thirds higher than comparison women⁷. The excess showed up mainly in women who didn’t take estrogen until about age 45⁷.

The same cohort found more new symptoms of depression and anxiety after surgery⁷. Women operated on before 49 who didn’t take estrogen until at least 50 also had a higher risk of cognitive impairment or dementia⁷. The Mayo authors concluded that estrogen may prevent some of these problems, but not all⁷.

These are observational studies. They show links, not proof, and the review gives relative risks, not absolute ones. It also focused on women at average risk of ovarian cancer⁷. If surgery is planned, it’s fair to ask whether your ovaries need to come out, and what that would mean for your age and history.

Your heart feels the change in your blood work first

Cardiovascular disease is the leading cause of death in women, yet in a 2017 survey only 56% of women knew it⁶. The 2020 AHA statement, led by Samar El Khoudary of the University of Pittsburgh, called the menopause transition a window when heart risk speeds up⁶.

In SWAN, total cholesterol, LDL (“bad”) cholesterol and apoB, a protein whose level reflects how many particles carry cholesterol into artery walls, rose sharply from the year before the final period to the year after⁶. That jump was separate from aging⁶.

Arteries stiffened, too: in SWAN, a measure of how fast a pulse travels through the main arteries rose 7.5% within about a year of the final period, beyond what standard risk factors explained⁶. Blood pressure, blood sugar and insulin changes, by contrast, tracked more with age than with menopause⁶.

The statement also found that HDL (“good”) cholesterol may protect less after menopause⁶. And women with hot flashes tend to have worse risk factors⁶. Our cholesterol article covers apoB and HDL, and a later article in this series covers hot flashes.

The opening: in SWAN, only 7.2% of midlife women consistently met physical activity guidelines, and fewer than 20% consistently ate a healthy diet⁶. Those are habits natural-health readers already prize, and the AHA statement calls midlife a critical window for starting prevention early⁶.

Hormone therapy is a separate question. OWH says it isn’t recommended to prevent heart disease or stroke¹⁰. The AHA statement says some forms may help the heart if started early in menopause, but not late, and that more research is needed⁶. Our article on observational studies explains how hormone therapy’s heart story was once misread.

Bone loss speeds up, and body fat moves inward

Bone loss speeds up after menopause, and low estrogen is its most common cause⁹. In the decade after menopause, some women lose as much as 25% of their bone mass⁹. About 1 in 4 women 65 and older has osteoporosis, and 1 in 3 women will likely break a bone because of it in her lifetime⁹.

Hormone therapy helps prevent bone loss and fractures⁸¹⁰. A later article in this series covers bone and muscle in midlife, including who should get a bone density test before 65. Our bone-loading article explains which exercises build bone.

Body shape changes, too. The AHA statement found that deep belly fat increases and lean muscle declines more sharply during the transition⁶. Weight gain around menopause is common, and OWH says regular exercise can help trim weight and waist size¹⁰. Our belly fat article covers SWAN’s body-composition findings in detail.

Memory dips during the transition, then recovers

About 60% of women report memory problems during the transition, said Gail Greendale, a UCLA physician who led a SWAN study of thinking skills¹¹. Her team tested 2,362 women aged 42 to 52 over four years¹¹.

People usually score better each time they repeat a test, because they learn it. That learning faltered in perimenopause¹¹. In late perimenopause, gains in processing speed were about 28% of what women saw before the transition, and gains in verbal memory shrank to about 7%¹¹.

Then the gains came back. After menopause, learning returned to premenopausal levels¹¹. “The good news is that the effect of perimenopause on learning seems to be temporary,” Greendale said¹¹.

Women who used hormones before their final period scored better, while hormone use after it was tied to worse scores. Greendale urged caution about these findings¹¹. OWH says hormone therapy isn’t used for brain fog alone, and researchers don’t yet know whether it lowers dementia risk¹⁴. Later articles in this series cover brain health.

The same transition carries different burdens

SWAN enrolled 3,302 women aged 42 to 52 in the mid-1990s: Black, Chinese, Japanese, Hispanic and white women at seven U.S. sites¹². A 2022 review led by Siobán Harlow of the University of Michigan compared Black and white participants across 25 years of SWAN research¹²¹³.

Black women reached their final period a median of 8.5 months earlier¹². After the researchers accounted for factors such as self-rated health, smoking, weight, education and work, the gap shrank to 3.1 months and was no longer statistically significant¹². The AHA statement adds that early natural menopause is more likely in Black and Hispanic women⁶.

At the start, 46% of Black women and 37% of white women reported hot flashes or night sweats in the previous two weeks¹². After adjustment, Black women were 50% more likely to have them, and had them longer¹². They were also less likely to use hormone therapy¹²¹³. At enrollment, 36.9% had high blood pressure, compared with 16.2% of white women, and 10.7% had diabetes, compared with 4.0%¹².

Care gaps followed. In SWAN’s mental health data, 43% of Black women reported getting treatment for emotional problems, compared with 65% of white women¹². Years later, when motion-sensing devices measured their sleep, 40% of Black women slept less than six hours, versus 19% of white women¹².

SWAN didn’t measure racism directly. It used money strain, discrimination and life stress as stand-ins, and Harlow called structural racism a major contributor to these gaps¹³. Your own experience of menopause depends on more than hormones.

After menopause: your health checklist

This checklist is our own design, built from the sources cited. Bring it to a checkup.

Area	What changes	What to check or ask	Source
Cholesterol	LDL and apoB rise around the final period	A lipid panel; whether apoB adds anything for you	6
Blood pressure and blood sugar	Rise mostly with age	Regular blood pressure checks; diabetes screening	6
Bone	Loss speeds up after menopause	Your fracture risk; when a bone density test makes sense	9
Body composition	More deep belly fat, less muscle	Waist size; strength training and activity	610
Memory	Temporary dip in perimenopause; learning recovers after menopause	Hormone therapy isn’t used for brain fog alone	1114
Vagina and bladder	Dryness, painful sex, urgency, repeat urinary infections	Treatments exist; a later article in this series covers them	14
Bleeding	Any bleeding 12 months or more after your last period isn’t normal	Make an appointment right away	414
Mood	Low mood or anxiety can arise	Talk with your provider; if you’re thinking of harming yourself, call or text 988	14
Menopause before 45, or ovaries removed	Higher bone, heart and diabetes risks	Tell your provider; ask about hormone therapy. For POI, the 2024 guideline lists a bone scan and cholesterol and diabetes tests at diagnosis, plus yearly blood pressure and weight checks	1568

For a medical emergency, OWH says to call 911 or go to the nearest emergency room⁴. Our guide to reproductive symptoms explains why bleeding after menopause usually isn’t cancer but still needs a visit.

How strong is the evidence?

Claim	Evidence level	What the research shows
Menopause speeds bone loss	Strong evidence	Consistent findings; low estrogen is the main cause9
Hormone therapy prevents bone loss and fractures	Strong evidence	Supported by The Menopause Society and OWH810
Early menopause is linked to higher heart risk	Strong evidence	Large cohorts agree; the absolute increase is modest36
Hormone therapy after POI or early surgical menopause protects heart and brain	Promising but early	Recommended by guidelines, though the POI guideline rates its evidence low or very low, largely observational178
Hormone therapy to prevent heart disease in general	Not enough evidence	Not recommended for this; timing questions remain610
Hormone therapy to sharpen memory after menopause	Not enough evidence	Not used for brain fog alone; dementia effect unknown1114

Questions readers ask

The bottom line

Menopause is a normal stage of life, and it marks a turning point for your health. Cholesterol rises, bone loss speeds up, fat shifts inward, and learning dips for a while before it recovers. Social conditions shape how hard the transition hits.

When menopause comes before 40 or 45, or surgery brings it on, the stakes rise, and guidelines call for closer checkups and a conversation about hormone therapy. For everyone, midlife is a key time to build the habits and get the checks that protect your heart and bones for the years ahead.

Related reading

• No single blood test confirms perimenopause, and your period calendar comes closer
• Your cholesterol panel leaves out two numbers that matter: ApoB and Lp(a)
• Exercise can reach the belly fat that matters, and liposuction can’t
• Why observational studies got smoking right and hormone therapy wrong
• Which reproductive symptoms can’t wait an hour, and how to sort the rest

Sources

1. ESHRE, ASRM, CRE WHiRL and IMS Guideline Group on POI (Panay N, et al.). “Evidence-based guideline: premature ovarian insufficiency.” Climacteric, 2024;27(6):510–520 (UCL Discovery copy). discovery.ucl.ac.uk
2. Monash Centre for Health Research and Implementation. “Guidelines for Premature Ovarian Insufficiency published in three leading journals.” December 17, 2024. mchri.org.au
3. Honigberg MC, Zekavat SM, Aragam K, et al. “Association of Premature Natural and Surgical Menopause With Incident Cardiovascular Disease.” JAMA, 2019 (UK Biobank publication record). pubmed.ncbi.nlm.nih.gov
4. Office on Women’s Health, U.S. Department of Health and Human Services. “Menopause basics.” Updated October 19, 2026. womenshealth.gov
5. Office on Women’s Health, U.S. Department of Health and Human Services. “Early or premature menopause.” Updated October 19, 2026. womenshealth.gov
6. El Khoudary SR, Aggarwal B, Beckie TM, et al. “Menopause Transition and Cardiovascular Disease Risk: Implications for Timing of Early Prevention: A Scientific Statement From the American Heart Association.” Circulation, 2020;142:e506–e532 (copy hosted by the Australasian Menopause Society), with the AHA’s “Top Things to Know” summary, November 30, 2020. pubmed.ncbi.nlm.nih.gov and professional.heart.org
7. Shuster LT, Gostout BS, Grossardt BR, Rocca WA. “Prophylactic oophorectomy in premenopausal women and long-term health: a review.” Menopause International, 2008;14(3):111–116 (PMC). pmc.ncbi.nlm.nih.gov
8. The North American Menopause Society (now The Menopause Society). “2022 Hormone Therapy Position Statement” (news release). July 7, 2022. menopause.org
9. Office on Women’s Health, U.S. Department of Health and Human Services. “Osteoporosis.” Updated April 28, 2026. womenshealth.gov
10. Office on Women’s Health, U.S. Department of Health and Human Services. “Menopause and your health.” Updated October 19, 2026. womenshealth.gov
11. American Academy of Neurology. “Menopause May Cause Temporary Decline in Memory and Learning” (news release on Greendale GA, et al., Neurology, 2009). May 2009. aan.com
12. Harlow SD, Burnett-Bowie SM, Greendale GA, et al. “Disparities in Reproductive Aging and Midlife Health between Black and White women: The Study of Women’s Health Across the Nation (SWAN).” Women’s Midlife Health, 2022;8:3 (PMC). pmc.ncbi.nlm.nih.gov
13. University of Michigan School of Public Health. “25 years of research shows insidious effect of racism on Black women’s menopausal transition, health.” February 23, 2022. sph.umich.edu
14. Office on Women’s Health, U.S. Department of Health and Human Services. “Menopause symptoms and relief.” Updated October 19, 2026. womenshealth.gov
15. National Institute on Aging. “Menopause.” National Institutes of Health, accessed October 2026. nia.nih.gov